Just to clarify on the 2G / 3G labels, since I don't think it's 100% clear in your comment:
2G is recovered (PCR-validated infection in past 6 months) or vaccinated
3G is that or (quick-)tested
2G+ is 2G and tested (exception: I've once earlier seen it used for 2G or PCR-tested)
Quick-tests at test centers (which are all over the place) were free for residents for a long time, then that got removed (IMHO a mistake), then made free again.
Actual proper checking of requirements was pretty terrible for a long time, from what I hear that's gotten a bit better.
Nearly everywhere I went required a few or test of the Coronapass app. Some scanned, some saw, and most required to see your id.
Went to St Pauli Weihnachtmarkt and the person I was with was rejected because he didn't have his id, but he did have his bank card with his name on it.
2G is recovered (PCR-validated infection in past 6 months) or vaccinated
3G is that or (quick-)tested
2G+ is 2G and tested (exception: I've once earlier seen it used for 2G or PCR-tested)
Quick-tests at test centers (which are all over the place) were free for residents for a long time, then that got removed (IMHO a mistake), then made free again.
Actual proper checking of requirements was pretty terrible for a long time, from what I hear that's gotten a bit better.