F-Droid - F-Droid is an interesting alternative for Android users who want to try something different and not have to use the Goole Play store all the time.
Kodi - Kodi is an award winning free and open source media player that got its start on the Xbox console.
APK Pure - Download apk for Android with APKPure APK downloader. NoAds, Faster apk downloads and apk file update speed. Best of all, it's free
Emby - media server for personal streaming movies tv music photos in mobile app or browser for all devices android iOS windows phone appletv androidtv smarttv and dlna.
APKMirror - Android Market and APK Downloads
Serviio - Web on Big Screen. Serviio enables playback of online sources like RSS feeds, live streams or web site content so that you can listen to your favourite podcasts or watch latest TV programmes published online.