MX Player, first released in 2011, has been one of the most popular Android video players for years. The app has now passed 500 million installations on the Play Store, marking another major milestone for the video player. MX Player doesn't appear to have been pre-installed on any Android devices, so that number should be 100% user downloads.
MX Player was purchased by Times Internet earlier this year for a whopping $200 million. Recent reviews indicate that the free version was recently updated with full-screen ads, but the app still maintains 4.5/5 stars on the Play Store.