Aptoide - Aptoide is a third party replacement for the traditional Google Play Store.
GOG.com - DRM-free game store, selling both new and old titles. No clients required.
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
itch.io - An online game marketplace and community.
Amazon Appstore - The Amazon Appstore is a place to purchase and download apps for your Android device.
GnuPlot - Gnuplot is a portable command-line driven interactive data and function plotting utility.