fix: prevent multiple app instances

src/main/index.js

@@ -6,6 +6,8 @@ import { format as formatUrl } from 'url';
 import ipcHandlers from './ipc-handlers';
 
 const isDevelopment = process.env.NODE_ENV !== 'production';
+const gotTheLock = app.requestSingleInstanceLock();
+
 process.env.ELECTRON_DISABLE_SECURITY_WARNINGS = 'true';
 
 // global reference to mainWindow (necessary to prevent window from being garbage collected)
@@ -67,6 +69,9 @@ async function createMainWindow () {
    return window;
 };
 
+if (!gotTheLock)
+   app.quit();
+else {
    // Initialize ipcHandlers
    ipcHandlers();
 
@@ -87,3 +92,4 @@ app.on('activate', () => {
    app.on('ready', () => {
       mainWindow = createMainWindow();
    });
+}