Yes, I work on FB apps that span multiple types of devices. You are correct in that only android users will see the request. I don't see it working all that wel

Yes, I work on FB apps that span multiple types of devices. You are correct in that only android users will see the request. I don't see it working all that well for you though, because the requestor won't know which friend uses android. So the requestor might need to send twenty requests to hit one friend with Android. Obviously, it is better to have an app that spans all the devices. That way Android users can request to iPhone, who can request to mobile web, who can request to canvas. Personally I think it is so important to be present on all of the devices that it is better to have slimmed down apps everywhere than one good app somewhere.