If you're on Android try installing the F-Droid app store, lots of open source apps are available on it (and Droid-ify is a good looking client for F-Droid if you want an app store UI with Material design)
I already have F-droid, Obtainium, etc, but these are pretty niche. It will be great to have something mass-market (not just for FOSS) that most consumers will have on their phones.