Where can i find a good acoustic guitar tuner?

I think the standard korg chromatic tuner everyone owns is really your best bet. Turn it on, play a string, keep plucking it while messing with the knob till you get it where it belongs. They don’t really get much easier or harder than that.

The term you are looking for is a “chromatic tuner”. There is plenty of free guitar tuner software available.

This might be the tuner that teira is referring to. It’s the most common. Cheap, simple, works. Korg CA-30 Chromatic Tuner

Boss TU-12 or TU-12H tuner. you can get em on ebay and they’re pretty reasonable. the problem with a bad or cheap tuner, is, they’ll drive you nuts with the inaccuracies. spend the extra couple bucks and you’ll be happy you did.