Awesome consept. If it worked on all/most pinball machines. This will however work only on newer Stern machines. That have it activated. That have paid the subscription fee. Etc.
Do most pinheads only own/play the latest Sterns?
Do pinheads that actually use an app for scoring want yet another app to use as well?
Eventually this will end up in how fast/easy/user friendly the app is, if you bother to use the app at all, especially when it is only for a handful spesific machines, and how many players actually use the app in the long run despite playing on Bally, Williams, CGC, JJP, Spooky machines etc. as well, maybe with other apps.
From the consumer/player perspective, a solution like this should have easily worked on all machines where Pinquest, Scorbit, Pindigo and PinballMap merged into one superb solution for us all.