https://github.com/consenlabs/token-core-android
https://github.com/consenlabs/token-core-ios

String prvKey = WalletManager.exportPrivateKey(ethereumWallet.getId(), SampleKey.PASSWORD);
System.out.println(String.format("PrivateKey: %s", prvKey));
String mnemonic = WalletManager.exportMnemonic(ethereumWallet.getId(), SampleKey.PASSWORD).getMnemonic();
System.out.println(String.format("Mnemonic: %s", mnemonic));
String json = WalletManager.exportKeystore(ethereumWallet.getId(), SampleKey.PASSWORD);
System.out.println(String.format("Keystore: %s", json));

// output:
// PrivateKey: f653be3f639f45ea1ed3eb152829b6d881ce62257aa873891e06fa9569a8d9aa
// Mnemonic: tide inmate cloud around wise bargain celery cement jungle melody galaxy grocery
// Keystore: {"id":"c7575eba-3ae3-4cc3-86ba-2eb9c6839cad","version":3,"crypto":{"ciphertext":"7083ba3dd5470ba4be4237604625e05fa6b668954d270beb848365cbf6933ec5","mac":"f4f9ea8d42ff348b11fc146c396da446cc975309b3538e08a58c0b218bddd15d","cipher":"aes-128-ctr","cipherparams":{"iv":"db3f523faf4da4f1c6edcd7bc1386879"},"kdf":"pbkdf2","kdfparams":{"dklen":32,"c":10240,"prf":"hmac-sha256","salt":"0ce830e9f888dfe33c31e6cfc444d6f588161c9d4128d4066ee5dfdcbc5d0079"}},"address":"4a1c2072ac67b616e5c578fd9e2a4d30e0158471"}