Privacy is very important to us. That is why the app asks for as few data as possible. Furthermore, we did not add any user behaviour tracking.
As for your data, we think we have only good news:
First off, understand that with this app, you make actual and direct contributions to the OpenStreetMap. Anything you contribute in this app is directly added to the map, there is no third party in-between the app and OSM infrastructure, like it is the case with wheelmap.org.
Editing the OpenStreetMap anonymously is not possible, so any changes you make are made with your OSM user account. This means, that the date, content and implicitly the location of your changes are visible publicly on the OpenStreetMap website and are attributable to your account.
As mentioned, the app directly communicates with OSM infrastructure. That is, with the Overpass API for downloading map data (which is anonymous) and with the OSM API for uploading changes.
To display the map, vector tiles are retrieved from JawgMaps. See their privacy statement for more information.