AirGap

With AirGap’s two device approach, you can sign transactions completely offline on a device without any network connectivity with the AirGap Vault application and broadcast them with your every-day smartphone with the AirGap Wallet app. Instead of installing AirGap Vault on an offline device, you can also install AirGap Vault and AirGap Wallet on your every-day phone and profit from added security through application sandboxing and app switching for communication. Based in Switzerland, AirGap is a BTC/ETH mobile digital wallet. It can be used to perform transactions and to manage crypto assets. The AirGap vault complements the AirGap wallet by providing the users with security features to safeguard BTC/ETH (it also has support for Bitcoin HD wallet), such as the possibility of being installed on a dedicated or old smartphone that has no connection to any network. The AirGap was developed by Papers.ch and it is an open source project.