[handedness]

I'm surprised that with the number of complaints about Google auth, FB and Twitter are what come to mind as viable alternatives.

I would consider using Apple for something like this. But limiting it to third-party auth is pretty unfriendly to users.

[acnops]

Ok, we will add user+pw. I've done some research in the meantime:

- FB is not that easy, since you can't set the email address as a required field. We use that to send the final render. We could let it be filled in in the app though.

- Twitter will probably be added

- Apple can be investigated