Google Play Store - Google Play Store is the official marketplace for apps, music, books, and other forms of media that are designed to be used on Android mobile devices. Read more about Google Play Store.
Amazon Appstore - The Amazon Appstore is a place to purchase and download apps for your Android device.
GetJar - Discover and play paid apps and games for free.
Ninite - Ninite is the easiest way to install software.
Aptoide - Aptoide is a third party replacement for the traditional Google Play Store.
AppCake - AppCake is a website and mobile app that gives you a place to download apps for your iPhone from. The site features all sorts of apps, from games to productivity based apps. Read more about AppCake.