I stand corrected.....
Since the tach function was not listed on the TrailTech Voyager page and I did not come across any screen shots showing a tach even in the user manual I assumed (Oops.....) it did not have that feature. Doing a search in the user manual .pdf document did list a tach on pages #7 and #24.
My point about the iPhone 3Gs GPS functions, with the free app I have, was more about the maps I get. In fact it actually helped me locate myself in the woods quicker than my Garmin 60C did awhile back. Yes I was surprised by that also.
And I do agree with you comment "....what it is designed for the Voyager works really well."
It has a lot of good features (see pg. 24 in the manual) that are nice to have all in one package taking up a small space on the bike. I was just disapointed that the GPS does not have more of the basic features most GPS users are used to getting even on the low $$$ units.
I'll edit my original post to state it does have a tach.
Past Bikes.....Check with my Wife.....I've lost count :-)