I have been using this app since it became available for the iPhone. I first used it on the first iPhone that I have owned, iphone 4. I have had no problems with it. I have always been able to update. You must be aware though, that if you have to restore your iPhone for any reason, the app will lose the authorization code. So if you do restore your iPhone to factory setting, when you restore the app, you must call the toll free number to get re-authorize or head to your local Realtor Association for them to do it for you!! I love the convenience of not having to carry the separate ekey device. I am only using the basic ekey subscription and it has always worked.
DJ Yoda 69 about Supra eKEY