iOS: We were fans of the original Prompt when it was released in 2011. Panic has updated its SSH iOS app with a bunch of new features, including sync, clips, TouchID lock and more.
The original Prompt was already one of the more powerful SSH apps on iOS, but Prompt 2 is a new app that's totally redesigned. The new version features everything you'd expect from an SSH app, including keyboard support, bookmarks of your favourite servers, autocomplete and folder support. It also includes Clips, which work like Text Expander for SSH, private key generation, and an open connection switch option that makes it easy to swap between different servers. As with a lot of Panic's apps, Prompt 2 is a little pricey at $12.99, but it's also easy to use and stable, which is really all you need in an SSH app.
Prompt 2 ($12.99) [iTunes App Store]