Hey ingumak.
I was testing gyroscope a while ago but decided to give it a whirl again recently.
It seems there has been tests on a few iOS platforms in here.
Gyroscope on iPad 1 seems to be supported. But iOS5 on the newer devices seems to work somewhat. But that's pretty much on Safari browsers. And I don't think Safari is on Android.
So it seems the answer to the gyroscope controls on mobile is sometimes yes and sometimes no.
The thread I mentioned above also says they got movement through the accelerometer, so it might be wise to explore that option. But still and yet the target platforms you plan to run your game on also matters. As with appMobi and CocoonJS export options now available,whether these support device orientation and touch expressions is completely independent on whether or not a browser like Safari does.
I was testing on CocoonJS for Android 2.2 and the features did seem to be buggy. They did release a new update though, but to my despair all I get is a black screen with the fps showing as opposed to my objects originally showing up. The only things that didn't seem to be working were touch and gyro (not sure about accelerometer). The touch was returning 0 but I can't check the return of the gyro with the black screen bug.
Anyway, say Construct 2 is doing it's job on it's end, it would probably be best to to test out your target platform yourself or see if anyone around here has tested it. That would actually make for useful data..."Frameworks and Browsers that support Gyroscope and Accelerometer."
That's standards based technology for ya.