Crypto Ledger is an open source extension of the Crypto Ledger website. It makes use of the Crypto Ledger API to buy, sell, and monitor coins. The app was built using Kotlin and Android Studio. It uses coroutines and retrofit to make API calls, and fragments for navigation. The source code is available on GitHub: https://github.com/TMDStudios/crypto_ledger_app_kotlin

Buying and selling coins requires an API Key, while getting live price data does not.