IzzyOnDroid – an Android store for Free & Open Source Software. The apps are free (as in „free beer“ and as in „free speech“) and Open Source.
Builds for IzzyOnDroid are directly from developers and signed by developers. This enables very fast publishing of new releases (whereas F-Droid re-builds all apps from the source).
There are several ways to install and update CoMaps via IzzyOnDroid, see here:
Direct link to the fdroid repo info page. You can add it by URL or QR code in the “Repositories” menu in the fdroid settings. Apps in there are a bit more wild west so check the source before you install unknown stuff from it.
https://apt.izzysoft.de/fdroid/