I have been working as professional Android Developer since 2014 and developed more that 50 applications and many of them are on Play Store.
I can help you develop Android Application using Java/Kotlin using latest Android build tools and Android studio, If you want to update your old Android application i can also help you update application without breaking the logic. Further more i can also help integrate Google Maps, Firebase, Admob and other third party services and API's
Tools:
Android Studio
Android SDK
Java/Kotlin
Google Maps
Google Firebase
Google Firebase Analytics
Google AdMob
Parse
Mapbox (Map, Routing, Styling)
OkHttp
Retrofit
Picasso