Here is a interesting iPhone setup for your bike. It gives information about the bike. From the web site it states; "the info available to the biker include a speed meter, gear indicator, engine temp, tacho meter, turn signal, compass, battery voltage, and, my personal favorite for stoplight to stoplight blasts, a programmable shift light."

Sounds pretty good to me.

http://dailybikefeed.tumblr.com/post...alyzer-for-h-d

 

This is an interesting app. However, the price is just way too high. I can replace my speedo with an HD combo speedo/tach for about the same price. Also, if I went with the iPhone app for these instruments and then couldn't see the iPhone in full sunlight, then it would be a complete waste of money. It's just not worth the risk to me. Maybe if it was less than $100, it might be worth a try.