After upgrade my IPhone to IOS7, i can't edit "Spur Gear", "Pinion Gear" and "Drive Ration" value in Traxxas Link App.
It's a good thing if you can actually still use the app.
Some other apps you just can't open them
Just gotta wait til an update is available, most likely.
I have the same problem it has been driving me nuts. I didn't think about the IOS7 being the problem but I am sure it is i hope they come out with a update soon
Same here, used to work so I assume it is ios7 related.
I just use old iTouches and don't bother upgrading OS or Traxxas Link app so I don't have to deal with these issues which keep cropping up with every update.