Wikimedia Commons only accepts videos in the WebM and Theora formats, which is not the format most smartphones store videos in. This means that re-encoding videos is necessary before uploading. Also, the web upload form easily gets reset on Android, so an app would probably be more reliable.
- Android app that uploads videos to Wikimedia Commons
- Before uploading, re-encodes videos to WebM (VP8 or VP9, latter preferred) or Ogg Theora
- Uploads in the background, so that I can do other things during that time
- Runs on Android 5+
- Free, ideally open source
Note: The Commons Mobile app does not handle videos, only pictures.