diff --git a/packages/redux-devtools-core/src/app/index.tsx b/packages/redux-devtools-core/src/app/index.tsx
index 335e2c3e..52641595 100644
--- a/packages/redux-devtools-core/src/app/index.tsx
+++ b/packages/redux-devtools-core/src/app/index.tsx
@@ -9,7 +9,7 @@ import { StoreState } from './reducers';
 import { ConnectionOptions, StoreAction } from './actions';
 
 interface Props {
-  socketOptions: ConnectionOptions;
+  socketOptions?: ConnectionOptions;
 }
 
 class Root extends Component<Props> {
diff --git a/packages/redux-devtools-core/src/index.ts b/packages/redux-devtools-core/src/index.ts
deleted file mode 100644
index 29d541ff..00000000
--- a/packages/redux-devtools-core/src/index.ts
+++ /dev/null
@@ -1,8 +0,0 @@
-function injectedScript() {
-  /* eslint-disable-next-line no-console */
-  console.error(
-    "Not implemented yet. WIP. If you're looking for utils, import `redux-devtools-core/lib/utils`."
-  );
-}
-
-export default injectedScript;
diff --git a/packages/redux-devtools-core/index.tsx b/packages/redux-devtools-core/src/index.tsx
similarity index 94%
rename from packages/redux-devtools-core/index.tsx
rename to packages/redux-devtools-core/src/index.tsx
index bd23dae6..c40f8b2a 100644
--- a/packages/redux-devtools-core/index.tsx
+++ b/packages/redux-devtools-core/src/index.tsx
@@ -1,6 +1,6 @@
 import React from 'react';
 import { render } from 'react-dom';
-import App from './src/app';
+import App from './app';
 
 render(<App />, document.getElementById('root'));
 
diff --git a/packages/redux-devtools-core/src/utils/filters.ts b/packages/redux-devtools-core/src/utils/filters.ts
index d6607f6b..9c9644b1 100644
--- a/packages/redux-devtools-core/src/utils/filters.ts
+++ b/packages/redux-devtools-core/src/utils/filters.ts
@@ -1,4 +1,7 @@
 import mapValues from 'lodash/mapValues';
+import { PerformAction } from 'redux-devtools-instrument';
+import { Action } from 'redux';
+import { State } from '../app/reducers/instances';
 
 export const FilterState = {
   DO_NOT_FILTER: 'DO_NOT_FILTER',
@@ -6,19 +9,25 @@ export const FilterState = {
   WHITELIST_SPECIFIC: 'WHITELIST_SPECIFIC',
 };
 
-export function arrToRegex(v) {
+export function arrToRegex(v: string | string[]) {
   return typeof v === 'string' ? v : v.join('|');
 }
 
-function filterActions(actionsById, actionsFilter) {
+function filterActions(
+  actionsById: { [actionId: number]: PerformAction<Action<unknown>> },
+  actionsFilter: (action: Action<unknown>, id: number) => Action
+) {
   if (!actionsFilter) return actionsById;
-  return mapValues(actionsById, (action, id) => ({
+  return mapValues(actionsById, (action, id: number) => ({
     ...action,
     action: actionsFilter(action.action, id),
   }));
 }
 
-function filterStates(computedStates, statesFilter) {
+function filterStates(
+  computedStates: { state: unknown; error?: string | undefined }[],
+  statesFilter: (state: unknown, actionId: number) => unknown
+) {
   if (!statesFilter) return computedStates;
   return computedStates.map((state, idx) => ({
     ...state,
@@ -26,7 +35,17 @@ function filterStates(computedStates, statesFilter) {
   }));
 }
 
-export function getLocalFilter(config) {
+interface Config {
+  actionsBlacklist?: string[];
+  actionsWhitelist?: string[];
+}
+
+interface LocalFilter {
+  whitelist?: string;
+  blacklist?: string;
+}
+
+export function getLocalFilter(config: Config): LocalFilter | undefined {
   if (config.actionsBlacklist || config.actionsWhitelist) {
     return {
       whitelist: config.actionsWhitelist && config.actionsWhitelist.join('|'),
@@ -36,33 +55,53 @@ export function getLocalFilter(config) {
   return undefined;
 }
 
+interface DevToolsOptions {
+  filter?:
+    | typeof FilterState.DO_NOT_FILTER
+    | typeof FilterState.BLACKLIST_SPECIFIC
+    | typeof FilterState.WHITELIST_SPECIFIC;
+  whitelist?: string;
+  blacklist?: string;
+}
 function getDevToolsOptions() {
-  return (typeof window !== 'undefined' && window.devToolsOptions) || {};
+  return (
+    (typeof window !== 'undefined' &&
+      (window as { devToolsOptions?: DevToolsOptions }).devToolsOptions) ||
+    {}
+  );
 }
 
-export function isFiltered(action, localFilter) {
-  const { type } = action.action || action;
+export function isFiltered(
+  action: PerformAction<Action<unknown>> | Action<unknown>,
+  localFilter?: LocalFilter
+) {
+  const { type } = (action as PerformAction<Action<unknown>>).action || action;
   const opts = getDevToolsOptions();
   if (
     (!localFilter &&
       opts.filter &&
       opts.filter === FilterState.DO_NOT_FILTER) ||
-    (type && typeof type.match !== 'function')
+    (type && typeof (type as string).match !== 'function')
   )
     return false;
 
   const { whitelist, blacklist } = localFilter || opts;
   return (
-    (whitelist && !type.match(whitelist)) ||
-    (blacklist && type.match(blacklist))
+    // eslint-disable-next-line @typescript-eslint/prefer-regexp-exec
+    (whitelist && !(type as string).match(whitelist)) ||
+    // eslint-disable-next-line @typescript-eslint/prefer-regexp-exec
+    (blacklist && (type as string).match(blacklist))
   );
 }
 
-export function filterStagedActions(state, filters) {
+export function filterStagedActions(state: State, filters: LocalFilter) {
   if (!filters) return state;
 
-  const filteredStagedActionIds = [];
-  const filteredComputedStates = [];
+  const filteredStagedActionIds: number[] = [];
+  const filteredComputedStates: {
+    state: unknown;
+    error?: string | undefined;
+  }[] = [];
 
   state.stagedActionIds.forEach((id, idx) => {
     if (!isFiltered(state.actionsById[id], filters)) {
@@ -79,13 +118,13 @@ export function filterStagedActions(state, filters) {
 }
 
 export function filterState(
-  state,
-  type,
-  localFilter,
-  stateSanitizer,
-  actionSanitizer,
-  nextActionId,
-  predicate
+  state: State,
+  type: string,
+  localFilter: LocalFilter,
+  stateSanitizer: (state: unknown, actionId: number) => unknown,
+  actionSanitizer: (action: Action<unknown>, id: number) => Action,
+  nextActionId: number,
+  predicate: (currState: unknown, currAction: Action<unknown>) => boolean
 ) {
   if (type === 'ACTION')
     return !stateSanitizer ? state : stateSanitizer(state, nextActionId - 1);
@@ -97,9 +136,14 @@ export function filterState(
     localFilter ||
     (filter && filter !== FilterState.DO_NOT_FILTER)
   ) {
-    const filteredStagedActionIds = [];
-    const filteredComputedStates = [];
-    const sanitizedActionsById = actionSanitizer && {};
+    const filteredStagedActionIds: number[] = [];
+    const filteredComputedStates: {
+      state: unknown;
+      error?: string | undefined;
+    }[] = [];
+    const sanitizedActionsById: {
+      [id: number]: PerformAction<Action<unknown>>;
+    } = actionSanitizer && {};
     const { actionsById } = state;
     const { computedStates } = state;
 
diff --git a/packages/redux-devtools-core/src/utils/get-params.ts b/packages/redux-devtools-core/src/utils/get-params.ts
new file mode 100644
index 00000000..417ec500
--- /dev/null
+++ b/packages/redux-devtools-core/src/utils/get-params.ts
@@ -0,0 +1,4 @@
+declare module 'get-params' {
+  function getParams(func: (...args: any[]) => unknown): string[];
+  export default getParams;
+}
diff --git a/packages/redux-devtools-core/src/utils/importState.ts b/packages/redux-devtools-core/src/utils/importState.ts
index 11cf3222..1afe997f 100644
--- a/packages/redux-devtools-core/src/utils/importState.ts
+++ b/packages/redux-devtools-core/src/utils/importState.ts
@@ -1,8 +1,11 @@
 import mapValues from 'lodash/mapValues';
 import jsan from 'jsan';
-import seralizeImmutable from 'remotedev-serialize/immutable/serialize';
+import { immutableSerialize } from 'redux-devtools-serialize';
+import { Action } from 'redux';
+import Immutable from 'immutable';
+import { State } from '../app/reducers/instances';
 
-function deprecate(param) {
+function deprecate(param: string) {
   // eslint-disable-next-line no-console
   console.warn(
     `\`${param}\` parameter for Redux DevTools Extension is deprecated. Use \`serialize\` parameter instead:` +
@@ -11,8 +14,20 @@ function deprecate(param) {
 }
 
 export default function importState(
-  state,
-  { deserializeState, deserializeAction, serialize }
+  state: string,
+  {
+    deserializeState,
+    deserializeAction,
+    serialize,
+  }: {
+    deserializeState?: (state: string) => unknown;
+    deserializeAction?: (action: string) => Action<unknown>;
+    serialize?: {
+      immutable?: typeof Immutable;
+      refs?: (new (data: any) => unknown)[] | null;
+      reviver?: (key: string, value: unknown) => unknown;
+    };
+  }
 ) {
   if (!state) return undefined;
   let parse = jsan.parse;
@@ -21,19 +36,38 @@ export default function importState(
       parse = (v) =>
         jsan.parse(
           v,
-          seralizeImmutable(serialize.immutable, serialize.refs).reviver
+          immutableSerialize(serialize.immutable!, serialize.refs).reviver
         );
     } else if (serialize.reviver) {
       parse = (v) => jsan.parse(v, serialize.reviver);
     }
   }
 
-  let preloadedState;
-  let nextLiftedState = parse(state);
-  if (nextLiftedState.payload) {
-    if (nextLiftedState.preloadedState)
-      preloadedState = parse(nextLiftedState.preloadedState);
-    nextLiftedState = parse(nextLiftedState.payload);
+  let preloadedState: State | undefined;
+  let nextLiftedState: State = parse(state) as State;
+  if (
+    ((nextLiftedState as unknown) as {
+      payload?: string;
+      preloadedState?: string;
+    }).payload
+  ) {
+    if (
+      ((nextLiftedState as unknown) as {
+        payload: string;
+        preloadedState?: string;
+      }).preloadedState
+    )
+      preloadedState = parse(
+        ((nextLiftedState as unknown) as {
+          payload: string;
+          preloadedState: string;
+        }).preloadedState
+      ) as State;
+    nextLiftedState = parse(
+      ((nextLiftedState as unknown) as {
+        payload: string;
+      }).payload
+    ) as State;
   }
   if (deserializeState) {
     deprecate('deserializeState');
@@ -41,17 +75,19 @@ export default function importState(
       nextLiftedState.computedStates = nextLiftedState.computedStates.map(
         (computedState) => ({
           ...computedState,
-          state: deserializeState(computedState.state),
+          state: deserializeState(computedState.state as string),
         })
       );
     }
     if (typeof nextLiftedState.committedState !== 'undefined') {
       nextLiftedState.committedState = deserializeState(
-        nextLiftedState.committedState
+        nextLiftedState.committedState as string
       );
     }
     if (typeof preloadedState !== 'undefined') {
-      preloadedState = deserializeState(preloadedState);
+      preloadedState = deserializeState(
+        (preloadedState as unknown) as string
+      ) as State;
     }
   }
   if (deserializeAction) {
@@ -60,7 +96,7 @@ export default function importState(
       nextLiftedState.actionsById,
       (liftedAction) => ({
         ...liftedAction,
-        action: deserializeAction(liftedAction.action),
+        action: deserializeAction((liftedAction.action as unknown) as string),
       })
     );
   }
diff --git a/packages/redux-devtools-core/src/utils/index.ts b/packages/redux-devtools-core/src/utils/index.ts
index 45bd643c..c343b293 100644
--- a/packages/redux-devtools-core/src/utils/index.ts
+++ b/packages/redux-devtools-core/src/utils/index.ts
@@ -1,14 +1,24 @@
 import getParams from 'get-params';
 import jsan from 'jsan';
 import { nanoid } from 'nanoid/non-secure';
-import seralizeImmutable from 'remotedev-serialize/immutable/serialize';
+import { immutableSerialize } from 'redux-devtools-serialize';
+import Immutable from 'immutable';
+import { Action } from 'redux';
 
-export function generateId(id) {
+export function generateId(id: string | undefined) {
   return id || nanoid(7);
 }
 
-function flatTree(obj, namespace = '') {
-  let functions = [];
+// eslint-disable-next-line @typescript-eslint/ban-types
+function flatTree(
+  obj: { [key: string]: (...args: any[]) => unknown },
+  namespace = ''
+) {
+  let functions: {
+    name: string;
+    func: (...args: any[]) => unknown;
+    args: string[];
+  }[] = [];
   Object.keys(obj).forEach((key) => {
     const prop = obj[key];
     if (typeof prop === 'function') {
@@ -24,18 +34,23 @@ function flatTree(obj, namespace = '') {
   return functions;
 }
 
-export function getMethods(obj) {
+export function getMethods(obj: unknown) {
   if (typeof obj !== 'object') return undefined;
-  let functions;
-  let m;
-  if (obj.__proto__) m = obj.__proto__.__proto__;
-  if (!m) m = obj;
+  let functions:
+    | {
+        name: string;
+        args: string[];
+      }[]
+    | undefined;
+  let m: { [key: string]: (...args: any[]) => unknown } | undefined;
+  if ((obj as any).__proto__) m = (obj as any).__proto__.__proto__;
+  if (!m) m = obj as any;
 
   Object.getOwnPropertyNames(m).forEach((key) => {
     const propDescriptor = Object.getOwnPropertyDescriptor(m, key);
     if (!propDescriptor || 'get' in propDescriptor || 'set' in propDescriptor)
       return;
-    const prop = m[key];
+    const prop = m![key];
     if (typeof prop === 'function' && key !== 'constructor') {
       if (!functions) functions = [];
       functions.push({
@@ -47,15 +62,17 @@ export function getMethods(obj) {
   return functions;
 }
 
-export function getActionsArray(actionCreators) {
+export function getActionsArray(actionCreators: {
+  [key: string]: (...args: any[]) => unknown;
+}) {
   if (Array.isArray(actionCreators)) return actionCreators;
   return flatTree(actionCreators);
 }
 
-/* eslint-disable no-new-func */
-const interpretArg = (arg) => new Function('return ' + arg)();
+// eslint-disable-next-line @typescript-eslint/no-implied-eval
+const interpretArg = (arg: string) => new Function('return ' + arg)();
 
-function evalArgs(inArgs, restArgs) {
+function evalArgs(inArgs: string[], restArgs: string) {
   const args = inArgs.map(interpretArg);
   if (!restArgs) return args;
   const rest = interpretArg(restArgs);
@@ -63,8 +80,14 @@ function evalArgs(inArgs, restArgs) {
   throw new Error('rest must be an array');
 }
 
-export function evalAction(action, actionCreators) {
+export function evalAction(
+  action: string | { args: string[]; rest: string; selected: string },
+  actionCreators: {
+    [selected: string]: { func: (...args: any[]) => Action<unknown> };
+  }
+) {
   if (typeof action === 'string') {
+    // eslint-disable-next-line @typescript-eslint/no-implied-eval
     return new Function('return ' + action)();
   }
 
@@ -73,12 +96,17 @@ export function evalAction(action, actionCreators) {
   return actionCreator(...args);
 }
 
-export function evalMethod(action, obj) {
+export function evalMethod(
+  action: string | { args: string[]; rest: string; name: string },
+  obj: unknown
+) {
   if (typeof action === 'string') {
+    // eslint-disable-next-line @typescript-eslint/no-implied-eval
     return new Function('return ' + action).call(obj);
   }
 
   const args = evalArgs(action.args, action.rest);
+  // eslint-disable-next-line @typescript-eslint/no-implied-eval
   return new Function('args', `return this.${action.name}(args)`).apply(
     obj,
     args
@@ -86,7 +114,7 @@ export function evalMethod(action, obj) {
 }
 /* eslint-enable */
 
-function tryCatchStringify(obj) {
+function tryCatchStringify(obj: unknown) {
   try {
     return JSON.stringify(obj);
   } catch (err) {
@@ -94,11 +122,26 @@ function tryCatchStringify(obj) {
     if (process.env.NODE_ENV !== 'production')
       console.log('Failed to stringify', err);
     /* eslint-enable no-console */
-    return jsan.stringify(obj, null, null, { circular: '[CIRCULAR]' });
+    return jsan.stringify(
+      obj,
+      (null as unknown) as undefined,
+      (null as unknown) as undefined,
+      ({
+        circular: '[CIRCULAR]',
+      } as unknown) as boolean
+    );
   }
 }
 
-export function stringify(obj, serialize) {
+export function stringify(
+  obj: unknown,
+  serialize?:
+    | {
+        replacer?: (key: string, value: unknown) => unknown;
+        options?: unknown | boolean;
+      }
+    | true
+) {
   if (typeof serialize === 'undefined') {
     return tryCatchStringify(obj);
   }
@@ -106,23 +149,44 @@ export function stringify(obj, serialize) {
     return jsan.stringify(
       obj,
       function (key, value) {
-        if (value && typeof value.toJS === 'function') return value.toJS();
+        if (value && typeof (value as any).toJS === 'function')
+          return (value as any).toJS();
         return value;
       },
-      null,
+      (null as unknown) as undefined,
       true
     );
   }
-  return jsan.stringify(obj, serialize.replacer, null, serialize.options);
+  return jsan.stringify(
+    obj,
+    serialize.replacer,
+    (null as unknown) as undefined,
+    serialize.options as boolean
+  );
 }
 
-export function getSeralizeParameter(config, param) {
+export function getSeralizeParameter(
+  config: {
+    serialize?: {
+      immutable?: typeof Immutable;
+      refs?: (new (data: any) => unknown)[] | null;
+      replacer?: (key: string, value: unknown) => unknown;
+      options?: unknown | boolean;
+    };
+  },
+  param: string
+):
+  | {
+      replacer?: (key: string, value: unknown) => unknown;
+      options: unknown | boolean;
+    }
+  | undefined {
   const serialize = config.serialize;
   if (serialize) {
     if (serialize === true) return { options: true };
     if (serialize.immutable) {
       return {
-        replacer: seralizeImmutable(serialize.immutable, serialize.refs)
+        replacer: immutableSerialize(serialize.immutable, serialize.refs)
           .replacer,
         options: serialize.options || true,
       };
@@ -131,7 +195,12 @@ export function getSeralizeParameter(config, param) {
     return { replacer: serialize.replacer, options: serialize.options || true };
   }
 
-  const value = config[param];
+  const value = (config as {
+    [param: string]: {
+      replacer?: (key: string, value: unknown) => unknown;
+      options: unknown | boolean;
+    };
+  })[param];
   if (typeof value === 'undefined') return undefined;
   // eslint-disable-next-line no-console
   console.warn(
@@ -139,12 +208,15 @@ export function getSeralizeParameter(config, param) {
       ' https://github.com/zalmoxisus/redux-devtools-extension/releases/tag/v2.12.1'
   );
 
-  if (typeof serializeState === 'boolean') return { options: value };
-  if (typeof serializeState === 'function') return { replacer: value };
   return value;
 }
 
-export function getStackTrace(config, toExcludeFromTrace) {
+export function getStackTrace(
+  // eslint-disable-next-line @typescript-eslint/ban-types
+  config: { trace?: () => {}; traceLimit: number },
+  // eslint-disable-next-line @typescript-eslint/ban-types
+  toExcludeFromTrace?: Function | undefined
+) {
   if (!config.trace) return undefined;
   if (typeof config.trace === 'function') return config.trace();
 
@@ -169,7 +241,7 @@ export function getStackTrace(config, toExcludeFromTrace) {
     typeof Error.stackTraceLimit !== 'number' ||
     Error.stackTraceLimit > traceLimit
   ) {
-    const frames = stack.split('\n');
+    const frames = stack!.split('\n');
     if (frames.length > traceLimit) {
       stack = frames
         .slice(0, traceLimit + extraFrames + (frames[0] === 'Error' ? 1 : 0))
diff --git a/packages/redux-devtools-core/test/app.spec.tsx b/packages/redux-devtools-core/test/app.spec.tsx
index 71b42159..d7ce85ee 100644
--- a/packages/redux-devtools-core/test/app.spec.tsx
+++ b/packages/redux-devtools-core/test/app.spec.tsx
@@ -1,7 +1,7 @@
-import React from 'react';
+import React, { Component } from 'react';
 import { Provider } from 'react-redux';
 import { createStore, applyMiddleware } from 'redux';
-import { mount } from 'enzyme';
+import { mount, ReactWrapper } from 'enzyme';
 // import { mountToJson } from 'enzyme-to-json';
 import App from '../src/app/containers/App';
 import api from '../src/app/middlewares/api';
@@ -10,7 +10,7 @@ import rootReducer from '../src/app/reducers';
 import { DATA_TYPE_KEY } from '../src/app/constants/dataTypes';
 import stringifyJSON from '../src/app/utils/stringifyJSON';
 
-let wrapper;
+let wrapper: ReactWrapper<unknown, unknown, Component>;
 
 const store = createStore(rootReducer, applyMiddleware(exportState, api));
 
diff --git a/packages/redux-devtools-core/webpack.config.ts b/packages/redux-devtools-core/webpack.config.ts
index 342b9751..75d1c5ef 100644
--- a/packages/redux-devtools-core/webpack.config.ts
+++ b/packages/redux-devtools-core/webpack.config.ts
@@ -6,7 +6,7 @@ import ForkTsCheckerWebpackPlugin from 'fork-ts-checker-webpack-plugin';
 module.exports = (env: { development?: boolean; platform?: string } = {}) => ({
   mode: env.development ? 'development' : 'production',
   entry: {
-    app: './index',
+    app: './src/index',
   },
   output: {
     path: path.resolve(__dirname, `build/${env.platform as string}`),
diff --git a/packages/redux-devtools-serialize/src/immutable/index.ts b/packages/redux-devtools-serialize/src/immutable/index.ts
index b8fd874b..08382573 100644
--- a/packages/redux-devtools-serialize/src/immutable/index.ts
+++ b/packages/redux-devtools-serialize/src/immutable/index.ts
@@ -35,3 +35,4 @@ export default function (
     serialize: serialize,
   };
 }
+export { default as serialize } from './serialize';
diff --git a/packages/redux-devtools-serialize/src/index.ts b/packages/redux-devtools-serialize/src/index.ts
index 600d22c0..c2f42ae8 100644
--- a/packages/redux-devtools-serialize/src/index.ts
+++ b/packages/redux-devtools-serialize/src/index.ts
@@ -1,5 +1,4 @@
-import immutable from './immutable';
-
-module.exports = {
-  immutable: immutable,
-};
+export {
+  default as immutable,
+  serialize as immutableSerialize,
+} from './immutable';