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.
Udemy - Online Courses - Learn Anything, On Your Schedule
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
Adobe Learning Manager - Adobe Learning Manager (formerly Adobe Captivate Prime LMS) is easy to setup and helps in delivering engaging learning experiences in a personalized manner across devices.
APKMirror - Android Market and APK Downloads
Moodle - Moodle is the world's most popular learning management system. Start creating your online learning site in minutes!