The F-Droid Repository is an easily-installable catalogue of free and open source apps for Android. With F-Droid, it's easy to browse and install apps on your device, and keep track of updates. You can also browse the repository with a web browser, and download the app...
Aurora Store is an unofficial, FOSS client to Google's Play Store with an elegant design. Not only does Aurora Store download, update, and search for apps like the Play Store, it also empowers the user with new features.
Google Play (formerly the Android Market) is an online store by Google for Android devices. Browse and search for apps, books, and movie rentals from your web browser or Android device.
Aptoide is a distributed marketplace for mobile applications which runs on the Android operating system. In Aptoide, unlike the default Google Play Store, there is not a unique and centralized store but each user manages their own store.
APKPure is a totally free APK downloader for Android phone and tablet. Download apk directly from Android market even without Google play store account.
In an effort to make things easy, and maybe even fun, AndroidPolice.com created APK Mirror. Over the past several months, they've been working to build a smooth, reliable, trust-worthy site to host the downloads users love.
This is an F-Droid style repository for Android apps, provided by IzzyOnDroid. Applications in this repository are official binaries built by the original application developers, taken from their resp. repositories (mostly Github).
Uptodown is an international download site for mobile apps and desktop software. It was created on December 20, 2002, and is based in Málaga, Spain.
The Amazon Appstore is a place to purchase and download apps for your Android device. You can get a paid app for free every day, and see app recommendations based on your past Amazon purchases. You can also test apps on a simulated Android phone using a feature called “Test...
XDA Labs is a platform that allows developers to freely distribute and promote their apps -- without fear of having their products removed due to content restrictions or corporate censorship. Labs is free to use and developers keep 100% from Paypal and Bitcoin purchases.
According to the linked website (https://www.xda-developers.com/update-xda-labs/) this was shut down on 12/31/2020. Checking the linked GitHub repo (https://github.com/xda/XDA-Labs-Store-UI/) it has also been archived.