the hybrid works on all systems(old and new). the 3 wire only works on the latest system.
if you don't plan on traveling and know the track you run at uses a system it works with then get the cheaper 3 wire.
the app thing is a waste of time. it's dependent on if your local track is uploading the results to the site. I don't think I've ever seen one uploaded even big national events. it's not transponder dependent.
http://www.mylaps.com/data/sitemanag...patibility.png