The Wikipedia mobile app is a great way to access the site's massive wealth of information. The beta program for the Android app, as well as the separate Wikipedia Beta app, has just received a new update that drastically changes the reading list functionality.
The new interface looks a bit sleeker, but the main changes are functional. Multiple reading list articles can now be selected at once, and individual articles in reading lists can be saved/removed for offline reading. In addition, there's a new card on the home page that shows a random article from your reading list when you're offline.
You can try out the beta by joining the beta program on the main app, installing Wikipedia Beta from the Play Store, or downloading the APK from APKMirror.