Adoption of the online ID function has been incredibly slow. I haven't had a need for it yet. Some online banks allow you to open an account using it. You can also file taxes with it. Most applications require a NFC reader of some kind. But there is also an official app for iOS and Android which can be used to read the ID with your smartphone.
There is an online portal where you can read more about it:
There is an online portal where you can read more about it:
https://www.ausweisapp.bund.de/en/ausweisapp2-home/