polytune digital guitar tuner - $35 (Portland)

This clip on guitar tuner sells for $49 on Amazon.
Mine is like new, literally used 3 times.
This works perfectly and is very bright so it works well in dimly lit spaces and for outdoor playing.
It is a very sophisticated tuner.
You strum a chord, and from that strum it will tell you which of your 6 strings are out of town.
It's also more accurate than other clip-on tuners like a SNARK.