[SoftwareMaven]

Yes, but it needs to be done very carefully. As soon as your app is draining my battery or running my fans inappropriately, your app is gone. The key word, of course, is inappropriately. This puts caps on how much you can use, but it is still an essentially free resource.

[dinkumthinkum]

I think that's a major issue. The best way we know how to save battery live on devices now is not all these fancy computing techniques or what have you, it is the finish a computation and shut the device off as quickly as possible. So this strategy seems to run counter to that basic idea of power saving.