Android WhatsApp Admin Chat

I need a dedicated Android app that lets me handle customer conversations on WhatsApp without jumping between phones or the web dashboard. The core flow is straightforward: log in once with my WhatsApp Business credentials, see every open conversation in one place, and respond in real-time.

Key behaviours
• Send and receive messages instantly through the official WhatsApp Business API (or a proven gateway you recommend).
• Keep several customer chats open at once and let me switch between them with zero lag.
• Push notifications for new incoming messages, even when the app is in the background.

Deliverables
• Full Android Studio project with clean, well-commented source code.
• Signed APK ready for installation on my team’s devices.
• Short setup guide covering API credentials, build steps, and Play Store deployment if I decide to publish it later.

Acceptance criteria
1. I can add the cloud/API keys, build the app, and start chatting within 30 minutes following your guide.
2. Messages sent from the app appear in the customer’s WhatsApp thread instantly and vice-versa.
3. At least three concurrent chat windows can stay open without crashes or noticeable slow-downs.

If something in the WhatsApp ecosystem limits any of the above, tell me upfront and suggest a workaround. I’ll be prompt with feedback and test builds as soon as you share them.