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 Papersch and it is an open source project.