It's ok but there are better options out there IMHO: Peterson Strobostomp and Turbo Tuner are way more accurate if you set up guitars for a living, D'Addario makes a very slim one, Korg has a plethora of options in the Pitchblack range which are cheaper and smaller, PolyTune can help you tune multiple strings at a time.
Most of these options are cheaper which makes this kinda redundant.