http://www.amazon.com/gp/product/B004B0C1NE?smid=ATVPDKIKX0DER Not a huge sale ($85 normally $100), but since these pretty much don't go on sale in my experience it's a good time to buy. These provide an OBD2 interface to a smartphone with bluetooth, and require an app (free or paid) to use. I've got one and it's been very handy. I use Torque for Android phones. Might work with Rev for iPhones, but I don't know.
Damnit Mark! I just bought some hella 500ff's for $50 via an amazon lightning deal yesterday. Also just replaced my broken scantool earlier this week. Ugh, this is a great deal since like you said theyre rarely on sale... really awful timing for me though