Gtklick is a simple metronome with an easy-to-use GTK+ interface, supporting the JACK sound server.
It features different sounds to choose from, arbitrary meters and beat patterns, a speed trainer, and the ability to save and restore profiles. gtklick is implemented as a frontend to klick and uses OSC messages to communicate with the backend.
Using klick directly on the command line offers additional features like tempo maps and synchronization with JACK transport.