I am a solo freelancer who works with a small number of clients at a time, not an agency that tries to get as many clients as possible.
What I can do for you:
. Splash Screen with logo
. Back button
. No internet detection
. Pull down to Refresh
. Send you APK file
. All time Support
Whatever you update on your website... the app will automatically update. No need to manually update the app.
Since the app will be your income, you have to create a Google Play Console account, but you will get all kinds of help from me.