A few of the simple games on my phone (5S) end up with th phone getting really warm. These look like basic little games, that should hardly strain modern processing. For example my daughter put on "inside out", which is little more than puzzle bobble, a 20 year old type game that ran on much older machines, and the phone gets really warm after 5 minutes. Is a problem with the phone?, or bad writing of the apps? or an IOS bug? why do some simple games, cause the phone to get hot?