Without going into too much detail, it's basically Apple's fault. :) They changed something fundamental in the way resources are released in iOS 7 and simply didn't implement support for the old method in the iPad version of the OS the way they did for iPhone/iPod Touch.
This is why the game continued to function properly on those devices and why it was so difficult to determine the nature of the problem on iPads.
In the strictest sense, there was nothing wrong with my code. Apple just did a better job of managing the transition from iOS 6 to iOS 7 on iPhones and iPods than they did for iPads.
|I was also able to make a few basic iOS 7 user interface tweaks as part of this update.|
I'm honestly not sure if I'll be able to address any future issues that might be caused by inevitable iOS releases like 7.2 or 8.0, which is why Powergrids will continue to be free on the iOS App Store.
With any luck, it will remain playable on a wide range of devices for a good, long while but with the way Apple changes things unexpectedly in each new iOS version, there's no way to know for sure. :)
Note that this update is not an indication of a return to active development of this or any other game on my part. I simply had an opportunity to spend a little time trying to address the post-iOS-7 issues with Powergrids and managed to do so before that window closed.
If and when I return to full-time game development, I will be sure to let you all know. :)
Also note that those of you using iPhones, iPod Touches or iPads with versions of iOS prior to 7.0 do not need this update. It is strictly to address iPad-related issues introduced in iOS 7.0 and doesn't change the game itself in any way. 1.2 is the best, most up-to-date version of Powergrids for all devices running versions 4.3-6.x of iOS.
Thanks and enjoy!
Powergrids (Official Site)