diff --git a/app/plugins/extensions.js b/app/plugins/extensions.ts
similarity index 100%
rename from app/plugins/extensions.js
rename to app/plugins/extensions.ts
diff --git a/app/plugins/install.js b/app/plugins/install.ts
similarity index 87%
rename from app/plugins/install.js
rename to app/plugins/install.ts
index a1b44276..023fa111 100644
--- a/app/plugins/install.js
+++ b/app/plugins/install.ts
@@ -3,9 +3,9 @@ import queue from 'queue';
 import ms from 'ms';
 import {yarn, plugs} from '../config/paths';
 
-export const install = fn => {
+export const install = (fn: Function) => {
   const spawnQueue = queue({concurrency: 1});
-  function yarnFn(args, cb) {
+  function yarnFn(args: string[], cb: Function) {
     const env = {
       NODE_ENV: 'production',
       ELECTRON_RUN_AS_NODE: 'true'
@@ -30,7 +30,7 @@ export const install = fn => {
           } else {
             cb(null);
           }
-          end();
+          end?.();
           spawnQueue.start();
         }
       );
@@ -39,7 +39,7 @@ export const install = fn => {
     spawnQueue.start();
   }
 
-  yarnFn(['install', '--no-emoji', '--no-lockfile', '--cache-folder', plugs.cache], err => {
+  yarnFn(['install', '--no-emoji', '--no-lockfile', '--cache-folder', plugs.cache], (err: any) => {
     if (err) {
       return fn(err);
     }
diff --git a/app/utils/cli-install.js b/app/utils/cli-install.ts
similarity index 93%
rename from app/utils/cli-install.js
rename to app/utils/cli-install.ts
index f0da9f54..78a7c361 100644
--- a/app/utils/cli-install.js
+++ b/app/utils/cli-install.ts
@@ -79,13 +79,12 @@ const addBinToUserPath = () => {
   });
 };
 
-const logNotify = (withNotification, ...args) => {
-  //eslint-disable-next-line no-console
-  console.log(...args);
-  withNotification && notify(...args);
+const logNotify = (withNotification: boolean, title: string, body: string, details?: any) => {
+  console.log(title, body, details);
+  withNotification && notify(title, body, details);
 };
 
-export const installCLI = withNotification => {
+export const installCLI = (withNotification: boolean) => {
   if (process.platform === 'win32') {
     addBinToUserPath()
       .then(() =>
diff --git a/app/utils/map-keys.js b/app/utils/map-keys.ts
similarity index 69%
rename from app/utils/map-keys.js
rename to app/utils/map-keys.ts
index aac64ceb..52e097c9 100644
--- a/app/utils/map-keys.js
+++ b/app/utils/map-keys.ts
@@ -1,5 +1,5 @@
-const generatePrefixedCommand = (command, shortcuts) => {
-  const result = {};
+const generatePrefixedCommand = (command: string, shortcuts: string[]) => {
+  const result: Record<string, string[]> = {};
   const baseCmd = command.replace(/:prefix$/, '');
   for (let i = 1; i <= 9; i++) {
     // 9 is a special number because it means 'last'
@@ -11,14 +11,15 @@ const generatePrefixedCommand = (command, shortcuts) => {
   return result;
 };
 
-export default config => {
-  return Object.keys(config).reduce((keymap, command) => {
+export default (config: Record<string, string[] | string>) => {
+  return Object.keys(config).reduce((keymap: Record<string, string[]>, command: string) => {
     if (!command) {
-      return;
+      return keymap;
     }
     // We can have different keys for a same command.
-    const shortcuts = Array.isArray(config[command]) ? config[command] : [config[command]];
-    const fixedShortcuts = [];
+    const _shortcuts = config[command];
+    const shortcuts = Array.isArray(_shortcuts) ? _shortcuts : [_shortcuts];
+    const fixedShortcuts: string[] = [];
     shortcuts.forEach(shortcut => {
       let newShortcut = shortcut;
       if (newShortcut.indexOf('cmd') !== -1) {
diff --git a/app/utils/renderer-utils.js b/app/utils/renderer-utils.ts
similarity index 55%
rename from app/utils/renderer-utils.js
rename to app/utils/renderer-utils.ts
index 7ea6b643..4fc1d434 100644
--- a/app/utils/renderer-utils.js
+++ b/app/utils/renderer-utils.ts
@@ -1,14 +1,14 @@
-const rendererTypes = {};
+const rendererTypes: Record<string, string> = {};
 
 function getRendererTypes() {
   return rendererTypes;
 }
 
-function setRendererType(uid, type) {
+function setRendererType(uid: string, type: string) {
   rendererTypes[uid] = type;
 }
 
-function unsetRendererType(uid) {
+function unsetRendererType(uid: string) {
   delete rendererTypes[uid];
 }
 
diff --git a/app/utils/to-electron-background-color.js b/app/utils/to-electron-background-color.ts
similarity index 87%
rename from app/utils/to-electron-background-color.js
rename to app/utils/to-electron-background-color.ts
index 6612bf68..d9a5c988 100644
--- a/app/utils/to-electron-background-color.js
+++ b/app/utils/to-electron-background-color.ts
@@ -1,10 +1,10 @@
 // Packages
-const Color = require('color');
+import Color from 'color';
 
 // returns a background color that's in hex
 // format including the alpha channel (e.g.: `#00000050`)
 // input can be any css value (rgb, hsl, string…)
-module.exports = bgColor => {
+export default (bgColor: string) => {
   const color = Color(bgColor);
 
   if (color.alpha() === 1) {
diff --git a/app/utils/window-utils.js b/app/utils/window-utils.ts
similarity index 68%
rename from app/utils/window-utils.js
rename to app/utils/window-utils.ts
index 7ba4eb91..9a45f88b 100644
--- a/app/utils/window-utils.js
+++ b/app/utils/window-utils.ts
@@ -1,6 +1,6 @@
-const electron = require('electron');
+import electron from 'electron';
 
-function positionIsValid(position) {
+export function positionIsValid(position: [number, number]) {
   const displays = electron.screen.getAllDisplays();
   const [x, y] = position;
 
@@ -8,7 +8,3 @@ function positionIsValid(position) {
     return x >= workArea.x && x <= workArea.x + workArea.width && y >= workArea.y && y <= workArea.y + workArea.height;
   });
 }
-
-module.exports = {
-  positionIsValid
-};
diff --git a/package.json b/package.json
index 672d378b..c32c5f5f 100644
--- a/package.json
+++ b/package.json
@@ -303,6 +303,7 @@
     "@types/fs-extra": "8.0.1",
     "@types/mkdirp": "0.5.2",
     "@types/mousetrap": "^1.6.3",
+    "@types/ms": "0.7.31",
     "@types/node": "^12.12.21",
     "@types/pify": "3.0.2",
     "@types/plist": "3.0.2",
diff --git a/yarn.lock b/yarn.lock
index 5157da53..4916a502 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -708,6 +708,11 @@
   resolved "https://registry.yarnpkg.com/@types/mousetrap/-/mousetrap-1.6.3.tgz#3159a01a2b21c9155a3d8f85588885d725dc987d"
   integrity sha512-13gmo3M2qVvjQrWNseqM3+cR6S2Ss3grbR2NZltgMq94wOwqJYQdgn8qzwDshzgXqMlSUtyPZjysImmktu22ew==
 
+"@types/ms@0.7.31":
+  version "0.7.31"
+  resolved "https://registry.yarnpkg.com/@types/ms/-/ms-0.7.31.tgz#31b7ca6407128a3d2bbc27fe2d21b345397f6197"
+  integrity sha512-iiUgKzV9AuaEkZqkOLDIvlQiL6ltuZd9tGcW3gwpnX8JbuiuhFlEGmmFXEXkN50Cvq7Os88IY2v0dkDqXYWVgA==
+
 "@types/node@*", "@types/node@^12.0.12", "@types/node@^12.12.21":
   version "12.12.21"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-12.12.21.tgz#aa44a6363291c7037111c47e4661ad210aded23f"