Add advanced features to existing Android App

PenMe app enables its users to chat and communicate with handwritten messages. iOS version is more advanced than the Android version. This project is about adding missing features to the Android version. We are looking for an experienced Android developer with experience in technologies required for implementing the missing features. For example, handwriting canvas, custom keyboard, payment gateway SDKs for UPI, firebase caching and enabling offline operation etc. The Android version is written in Java. Familiarity with Swift code can be beneficial for leveraging iOS code. Current versions of the app are available at AppStore - https://apps.apple.com/us/app/penme/id1551913155 PlayStore - https://play.google.com/store/apps/details?id=com.indecagroup.penme"