Amazon Appstore - The Amazon Appstore is a place to purchase and download apps for your Android device.
Flickr - image and video hosting website
Aptoide - Aptoide is a third party replacement for the traditional Google Play Store.
Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
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.
PhotoPrism.app - PhotoPrism® is an AI-Powered Photos App for the Decentralized Web. It makes use of the latest technologies to tag and find pictures automatically without getting in your way. You can run it at home, on a private server, or in the cloud.