Android Application Latest Android compatible

I have a fully-functioning Android application that now needs a round of feature enhancement. The existing code compiles and runs, but I want fresh capabilities added and, while we are at it, a careful verification of the current implementation to be sure no hidden issues slip through... (Budget: ₹1500 - ₹12500 INR, Jobs: Android, Android App Development, Android SDK, Android Studio, Git, Java, Kotlin, Mobile App Development)