living in Germany: a non scientific poll showed that from the people following Corona 60% would install the app in Germany . It's build with SAP and T-Systems (T-Systems' involvement worries me actually). I'm not part of the 60% since I cannot just install an app without a proper check by IT bods, maybe later I will.
But one thing I don't understand is why the app wasn't built into the existing state KatWarn application, which concerned citizens have on their phones to know when catastrophes happen. In my circle of friends, most people have it. That app has a "guarding angel" mode, which checks your location to warn you of catastrophes around you OR you can just define areas of interest and not enable the location tracking.
On the whole health front, I fail to see why apple and co didn't extend the likes of HealthKit to cover and detect abnormal health situations also in regards to this type of sickness. Don't tell me that my apple watch doesn't have the data that shows something is off when I'm sick(being in bed with a cold and it's asking me to do sports). All these things should be open for reporting to the state, if I so choose (and I would), which would probably nullify the need for an explicit app from the state.