AncientApps

Here, I will list some of the apps that are Android 1.6+ supported. It is useful for app developers, people who want to use their old android(either in mobile or in emulator). Emulator does not ship with Market or Play Store. We have to download .apk files to install and use apps. Some mobiles does not ship with Market or Play Store. Older versions of .apks in F-Droid can be downloaded from F-Droid Archive repo. We can also download these in web at https://apt.izzysoft.de/fdroid/index.php?repo=archive

Many apps listed here are available in Android Freeware website and in Aptoide.

In these two scenarios, this list of apps will be helpful.

We can download older versions of Market or Play Store apps from Yalp Store or its derivatives.
Open a app in Yalp Store => Manual Download => Enter APP versionCode in it => Download.
versionCode can be found in sites like APKMirror, Android APK etc.,

Some third party websites are also available for downloading apks like APKMirror, Apkpure, ApkHere, ApkFind, uptodown, Apparchive, PHONEKY

A great list of apps can be found at IzzyOnDroid

Some APP information showing websites(not for downloading)
http://www.androlib.com
http://www.cyrket.com

Enjoy!