in addition to the web interface, keybase offers a client application for windows, mac, android, ios, and most desktop linux distributions, written in go with an electron front end. the app offers additional features to the website, such as the end-to-end encrypted chat, teams feature, and the ability to add files to and access private files in their personal and team keybase filesystem storage. each device running the client app is authorized by a signature made either by another device or the user's pgp key. each device is also given a per-device nacl key to perform cryptographic operations.