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
Mobango - Mobango is an alternative Android market.
APKMirror - Android Market and APK Downloads
Blapkmarket - Blapkmarket was one of the largest repositories of the Android apps over the internet that in addition to offering the paid apps of Google Play Store was offering its own developed apps for free as well.
Samsung Kies - Samsung Kies is a freeware software solution used to communicate between Mac or Window OS and more recently Samsung smartphones and tablets.
DownloadAtoZ - DownloadAtoZ is another app store that has the ability to download those Apks files that cannot be downloaded from Google Play.