Most of you know I have been a fan of TC Electronic’s Polytune Clip for a while now (review linked below). The Polytune Clip does really well with alternate and open-tunings on acoustic guitar; it latches on to notes quickly, has good tracking, and even does well reading the lower bass notes we sometimes tune our sixth strings to which other clip-on tuners can have trouble with. So I still love the PolyTune Clip even though I spend most of my time in open tunings and hardly ever use the PolyTune function. Recently, I learned that TC Electronic had partnered with music retailer Sweetwater to produce the Uni-Tune, which is just like the PolyTune Clip in every respect but without the PolyTune mode. (Also it is about $15 less expensive.)
As with the Polytune Clip, I found that TC Electronic’s Uni-Tune clip-on tuner latches on to notes quickly and accurately, has excellent tracking, and picks up the low 6th string bass notes well (even down as low as Bb). So if you use mostly open / altered tunings, or can otherwise live without the PolyTune function and want to save $15, you might consider the almost identical UniTune clip-on tuner from TC Electronic.