Resources to look at when implementing this:
https://github.com/bitcoin-core/secp256k1/tree/master/src https://github.com/bitcoin-wallet/bitcoin-wallet https://gitlab.com/axet/android-library/tree/9e5f11e78bea67f6e292114bdc8f0467cc216c7f/src/main/java/com/github/axet/androidlibrary/crypto https://github.com/mycelium-com/wallet-android https://github.com/thinkmobiles/BitcoinJ-Wallet-Sample-Android/blob/master/app/src/main/java/com/example/thinkmobiles/bitcoinwalletsample/main/MainActivityPresenter.java