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
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.
ApkPlayGame.com - Android Gaming at its best! Download thousands of Android Games fast, free and easy apk download! All game genres including 3D, HD, Open World, FPS, Battle Royale, Offline, Online Multiplayer, Time Killer...
APKMirror - Android Market and APK Downloads
Aurora Store - Aurora is a FOSS Play Store client that does not require a Google Account to download directly from Play Store. However you can login with your Google Account to download your already paid apps!
Amazon Appstore - The Amazon Appstore is a place to purchase and download apps for your Android device.