This is a nice plugin I got last night:
StroboSoft

It is basically the software version of their StroboFlip Tuner.
VERY accurate and also has 'sweetened' (tempered) tunings for Guitar which seem to be useful so far.

It can run in the background (at least with Nuendo on PC) and share the same input that I am recording from so I can check my pitch at any time.

MUCH better tuner than "C-Tuner" (which is free though).

jmp

My friend who passed last year (and we sold his stuff for the family) had two different digital Petersons (the big $300 bad boy and the StroboStomp pedal)...I have an analog 420 from long ago.

They may be a touch better than a $30 Boss...but, not much. Analog easily bests it...particularly if you're setting intonation, doing set up work. I suppose to tune Feiten guitars they may be nicer. I couldn't really tell a diff in the "sweetened" tunings. They still didn't beat just tuning it with the old "non virtual" strobe tuner.

I suppose if you're recording to a software DAW, it's convenient, though. Is there a shortcut key that brings it up?

The Strobosoft is WAY more sensitive than my Korg rack tuner or my cheap Boss tuners.

It displays 10th of a Cent and I suppose it depends upon the speed of the computer..but I was playing trumpet into it and it was perfectly tracking Vibrato.

I haven't studied up on the 'sweetened' tunings but in use, the results were good today.

I haven't set up a shortcut...but I use two monitors and just keep it open in the bottom right corner.

jmp

I love my Peterson...bought it to tune a pedal steel onstage and it was fantastic. Functional and accurate. I guess the cpu version would be just as good. Never messed wtih the sweetened tunings though...

Paul