Any apps or Health pass required for Germany?

bumping this

Folks might be reluctant to answer because it is still confusing, at least to me. This is What I am stumbling through. I hope someone corrects anything idiotic.

You do need to pre-register

https://www.einreiseanmeldung.de/#/

You must have proof of vaccine like your CDC card.

YOu can load your proof of vaccine on a digital record like the "Covpass-app"

https://www.digitaler-impfnachweis-app.de/en/faq/

I see folks mentioning a contract tracing app: Luca. Its use seems to be hit or miss by areas.

https://apps.apple.com/us/app/luca-app/id1531742708

If I sound knowledgeable, it is far from true.

You are required to show proof of vaccination, of recovery, or of a recent test ("3G rule") whenever you want to sit down in a restaurant or visit venues, and those places are required to get your contact information for contact tracing. You can do that using an app, or the old-fashioned way, on paper. I carry a copy of my vaccination document with me, and for contact tracing, I fill out a slip of paper. Works just as well.

There are basically three relevant apps: The Corona-Warn-App, CovPass and Luca. As far as I am aware, you can upload your vaccination information in all three of them. The Luca app is also widely used for contact tracing in restaurants etc. The first two apps are open source and well-examined regarding data privacy. I would not vouch for that in the Luca app.

As an old guy without a smartphone, I did fine with my CDC card. I had to fill out a contact tracing form (basically my name and e-mail) to get into places in Potsdam, which is in the state of Brandenburg, but not in Berlin, which is a separate state. You'll find variations like this depending on what state(s) you're in.