F-Droid is a huge store of free and open source apps. F-Droid has a store of free and open source apps exclusively in an official app which can be installed on your Android device.
As compared to other app archives or stores all the content in F-droid is open source with no exceptions. Practically, it means that you will not find any famous or popular android apps in the catalogue of F-Droid.
You can download any of the available apps in F-Droid. The older versions of the apps are also available in F-Droid. This app lets you know about the updates of the apps you have download so that you update them timely.
F-Droid is an official app with a great archive of Android apps. You will find more than 1500 apps on F-Droid along with their older versions. The app has a user-friendly interface. Enjoy free and open source apps with F-Droid!