M-Pesa Android App Integration

My Android app is still in development and I now need M-Pesa added as the primary payment option. The core screens and backend endpoints are already taking shape; what remains is a fully working, secure M-Pesa checkout flow built with Safaricom’s Daraja API. You will: • Wire the app to initiate STK Push, handle callbacks, and display clear success / failure states. • Implement proper token generation, timestamp signing, and error handling so transactions comply with Safaricom guidelines. • Provide concise setup notes that let my team rebuild the feature in Android Studio (Java or Kotlin) and test it on a sandbox before we go live. I will grant access to the current Git repository, test credentials, and any additional endpoints you may need. Once your integration passes sandbox tests we can switch to production keys for a final round of verification. If you have recent experience rolling out Daraja-based payments in Android apps, I’d love to see a quick example or two.