Very feasible, it is how your TV remote works... However, current-gen iPhones have IR filters on their normal (i.e. non-selfie) cameras, so this technology can'

Very feasible, it is how your TV remote works... However, current-gen iPhones have IR filters on their normal (i.e. non-selfie) cameras, so this technology can't be applied through a firmware update. I think it could be made more effective using radio waves.