This open-source and privacy-respecting app will install from a number of popular locations such as GitHub, GitLab, Codeberg, F-Droid, IzzyOnDroid, SourceForge, Huawei AppGallery, APKPure, and many more.
The Obtainium app is ideal if you already avoid the Google Play Store and prefer to get your apps from these locations, where the source code is published directly. This is also suited to users who like to get the latest pre-releases for the developers, to test out. For those who really value privacy and a de-Googled experience, then they will usually already be sourcing their apps manually from these locations. This app makes that process easier.
The onus though is on the user of this app, especially the first time when selecting the source, to be very sure it is the correct and valid source. This is not an official Play Store where that sort of validation is ‘most’ done for you. So, if you are a search, click to install person without worrying, then you may be better off with using the official Play Store, from a security perspective, or possibly the F-Droid app store.
The app tracks updates locally from the app, so it is not relying on any cloud notification pushes.