Thomann CTG-10 Clip Tuner

The "Thomann CTG-10 Clip Tuner" is one of the cheapest tuners you can buy, because of the low price you could be forgiven for thinking it's not going to much use but it's actually a pretty accurate and useful little tuner.
I usually tune with a BOSS TU-3 pedal tuner when I'm using on my pedal board but thought a little clip on tuner would be useful so that I could tune up without having to plug in and power up my pedal board for a quick practice session, the CTG-10 couldn't be handier for the job.
So far I have used it on my Fender Stratocasters, Fender Telecasters, Fender Mustang, Gibson Les Paul, Gibson SG, Gibson ES335, Epiphone Casino, Danelectro DC59 as well as my Gibson Hummingbird, Martin D28 and Art & Lutherie acoustics and the clip has accommodated all the different headstock shapes and thicknesses with ease.
The tuner is very simple and intuitive to use, a single button turns the unit on and off and the same button toggles between the three modes which are "guitar", "bass" and "chromatic".
To turn the tuner on the button needs to be held down for a couple of seconds so it won't be turned on accidentally in a gig bag or case.
The screen is easy to read and is bright enough to use in the dark but can be a little difficult to see it in daylight or under bright lights.
I have experimented using it along with my BOSS TU-3 and the results are pretty much the same.
It usually works as soon as it's clipped on and only very invasion ally do I need to reposition it to get it to work.
It's small enough that it can be left on the guitar when put away into a hard case and it's cheap enough that you can have one in every case.
All in all a very handy and capable little tuner, really very good value for money.

Incredibly good money for value purchase.

I got this as part of the bundle of my first acoustic guitar and used it constantly ever since (> 6 months). You can use it for chords (useful when you start learning) or just tune your guitar strings. You can also tune bass, which is a nice extra (didn't use it for that, as I don't own a bass yet). The screen turns green when you hit the perfect pitch, which is a nice visual clue.

Be aware that this tuner must be clipped to the guitar in order to process sound. For an acoustic, clip it around the rosette, and for the electric, clip it to the headstock.

I know it's just common sense, but it makes so much of a difference to practice with your guitar always in tune.