App store offers some applications for video recording. But I think they are all chargeable. In the 1st generation iPhone, its possible to jailbreak the phone which allows you to add installer in the phone such as Cydia. And that is pretty much like App store, (but there's more free applications). In cydia you can find application named Cycorder which is free video recorder. Hope this helps
Btw nice speedruns Yogy!