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
UCheck - UCheck is a tool that will help you to keep your software updated.
Amazon Appstore - The Amazon Appstore is a place to purchase and download apps for your Android device.
Avira Software Updater - Application that searches updates for software on your computer
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.
HEIMDAL FREE - HEIMDAL FREE is an application to automate your device software updates in order to improve your security.