File Manager File Explorer - File Manager File Explorer is a fully-featured file explorer and app manager to help with file transfer and accessing files and documents.
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.
Solid Explorer - Solid Explorer is a powerful Android file manager featuring access to most popular cloud storages, root access and easy extensibility.
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
File Commander – File Manager/Explorer - File Commander – File Manager/Explorer is a world’s leading and powerful file manager that lets you handle any file on your Android device, cloud storage or network location via the clean and intuitive interface.
APKMirror - Android Market and APK Downloads