While the Google Playstore is the central (and official) place for Android apps, there are other sources available. If your question is about them, this might be the correct tag. Please read the full tag wiki for more details.
What are "alternative markets"?
Usually, an Android user loads his apps from Google's Playstore. But not all devices are equipped with the required Google-Play-App, and sometimes things simply disappear from the Playstore (often for good reasons, but not always). So there are other sources one can find apps. Plenty of sources. To not have a separate tag for each of them, we have this tag. It is also useful if your issue does not relate to a specific market place, but is about "alternative markets" in general.
What markets are available?
If your issue is with a special market place, one of the following tag might be better suiting:
- Uptodown: free apps only. Own app to install apps and keep them up-to-date. Some security checks in place (e.g. VirusTotal).
- XDA Labs: though an app for the XDA forum, it also includes an AppStore
- amazon-appstore: the Amazon appstore, usually frequented by Kindle devices, is available to other Android devices as well. To take a look, you can visit its homepage with your browser
- Android Drawer offers to download
.apkfiles of free apps. Here you can also find older versions of apps
AndroidPIT also has an own "market app", pointing to its own storeclosed at 2014-12-31 APKTOPoffers to download free apps (seems no longer to exist)
- APKMirror offers free apps from Play Store, including "previous versions". For reference, see: Is apkmirror.com safe?
- app-brain: an alternative Front-End to the Google Playstore (not a separate market place). You can also visit them on their website.
- Aptoide hosts multiple repositories with Android apps, which can be accessed e.g. using the Aptoide app (you also can directly download the
.apkfiles with your web browser). See also: How safe is it to use Aptoide?
- F-Droid is a place where one can find free and open-source apps. Being a fork of Aptoide, it also offers multiple repositories, with the main repo (and its archive counterpart) administered by the F-Droid staff directly.
- google-play-store: the official market place for Android apps
- Samsung offers his own app store
- SlideMe also is an app market
- Samsung, Archos, LG, and other manufacturers run their own app stores
This is just a selection, there are many more. Often manufacturers have setup their own market place, like e.g. Samsung and LG... For more details, also see: What are the alternative Android app markets?