I am a huge fan of the Peterson V-SAM. I do teach the use of tuners to students primarily for learning where he partials on a brass instrument are and then quality tone production via the strobe. If the embouchure and breath are pure each band on the strobe can be stopped. I have a Conn Strobotuner with 12 wheels for that purpose. The metronome and drone features are excellent on the VSAM as well. For guitars, Peterson describes sweetened tunings and how to custom program your own temperaments. A non strobe tuner is just useless in my not so honest opinion. Of course the ultimate goal is to develop the ear but often in a live band situation being able to plug into the tuner and reset your custom tuning in a thrice is useful.
The Strobosoft program is available on ipod touch/iphone but you lose the oter benefits of the VSAM.