The Cherub has a built-in metronome, which is pressing for 1-2 seconds the Mode button.
Once the metronome is activated, one tap on the On/Off butoon, activates the metronome to the previous setting e.g. 100bpm, indicated by a moving bar on the front panel display.
The tempo can be adjusted by tapping the up/down buttons at the front of the device, and the supported range is 30bmp to 230 bmp.
The beat can be adjusted by tapping the mode button at the front of the device, and it supports -/4, 1/4, 2/4, 3/4, 4/4, 3/8 and 6/8 beats.
The value can be adjusted by tapping the value button at the front of the device, and it supports one quarter note, two eighth notes, four sixteenth notes, doted eight note, and rest and eight note.
I found that the metronome feature really useful, as you need a metronome that uses sound in order to practice. Also, having an earphone can spare your family/friends from the headache, right?
Finally, when compared to a mobile app tuner such as iPhone GuitarTuner, reviewed here, you find that the mobile apps provide additional features such as chord and scale charts which are very useful. You don't expect that from a tiny digital tuner, I know, but still, having a complete chords database with you is a nice feature.