Question: Xabber is available on the Android Play Store and another software repository that contains only apps that are what ?

Context paragraphs:
Power Rangers: Legacy Wars: Power Rangers: Legacy Wars is a video game based on the 2017 film "Power Rangers", created by San Francisco-based game developer nWay with characters from the movie and the TV show.  The game was featured on Amazon, Apple's AppStore and Google Play Store.  The game got top position among free apps on AppStore and second position on Android Play Store.

List of Google apps for Android: The list of Google apps for Android lists the mobile apps developed by Google for its Android operating system.  All of these apps are available for free from the Google Play Store, although some may not show up in search results if they are listed as incompatible with your device (even though they may still function from an *. apk).  Some of Google's apps may be pre-installed on some devices, depending upon the device manufacturer and the version of Android.  A few of these apps, such as Gboard, are not supported on older versions of Android.

Definitive software library: A definitive software library (DSL) is a secure location, consisting of physical media or a software repository located on a network file server, in which the definitive authorized versions of all software configuration items (CIs) are stored and protected.  The DSL is separate from development, quality assurance or production software storage areas.  It contains master copies of all controlled software and includes definitive copies of purchased software, as well as licensing information for software developed on-site or purchased from an external vendor.  All related documentation, related to any software stored in the DSL, is also stored in the DSL.

Xabber: Xabber (from XMPP and Jabber) is a XMPP client for the Android Operating System.  It is developed as an open source Project on GitHub and is licensed under the GNU/GPL v.3 license.  The original developers are from a software company called Redsolution, Inc.  Xabber is available on the Android Play Store and on F-Droid.

F-Droid: F-Droid is a software repository (or "app store") for Android applications, similar to the Google Play store.  The main repository, hosted by the project, contains only apps that are free and open-source software.  Applications can be browsed and installed from the F-Droid website or client app without the need to register for an account.  "Anti-features" such as advertising, user tracking, or dependence on non-free software are flagged in app descriptions.  The website also offers the source code of applications it hosts, as well as the software running the F-Droid server, allowing anyone to set up their own app repository.

Google Opinion Rewards: Google Opinion Rewards is a survey mobile app for Android developed by Google.  It allows users to answer surveys and earn Google Play credits which can be redeemed by buying paid apps from Google Play Store.  Users in the available countries who are over 18 years old are eligible.

List of most downloaded Android applications: This is a list of most downloaded Android applications that includes most of the free apps that have been downloaded more than 100 million times and most of the paid apps that have been downloaded over one million times on unique Android devices; these are listed in the tables below.  There are numerous Android apps that have been downloaded over one million times from the Google Play app store and it was reported in February 2017 that over 169 apps have been downloaded at least 100 million times and over 2,392 apps have been downloaded at least ten million times; the barrier for entry on this list is set at 100 million for free apps to limit its size.  Many of the applications in this list are distributed pre-installed on top-selling Android devices and may be considered bloatware by some people because users did not actively choose to download them.

Microsoft Office mobile apps: Microsoft Office mobile apps are productivity mobile apps developed by Microsoft for Windows 10, Windows 10 Mobile, iOS, Android, and Chrome OS.  The core apps are Word, Excel, PowerPoint, and OneNote.  Other Office apps, including Sway, Skype for Business, and SharePoint Newsfeed are available for download from the mobile app store on supported devices and platforms.  They are meant to be compatible with desktop versions of the office suite.  The suite of apps is free of charge for consumers with devices smaller than 10.1 in , but business customers need to purchase an Office 365 subscription to take full advantage of the suite on larger screens.

Samsung Galaxy Apps: Samsung Galaxy Apps, formerly known in feature phones as Samsung Apps is an app store used for devices manufactured by Samsung Electronics that was launched in September 2009.  The service is primarily shipped on Samsung Galaxy smartphones, Samsung Gear and feature phones (such as the Samsung REX and Duos) The store is available in 125 countries and it offers apps for Android, Windows Mobile and Bada platforms.  Apps from this store are updated by notifying the user via the Samsung Push Service, which has been installed in over one billion smartphones over the years.

Google Docs, Sheets, and Slides: Google Docs, Google Sheets, and Google Slides are a word processor, a spreadsheet and a presentation program respectively, all part of a free, web-based software office suite offered by Google within its Google Drive service.  The three apps are available as web applications, and as mobile apps for Android and iOS.  The apps are compatible with Microsoft Office file formats.  The suite also consists of Google Forms (survey software), Google Drawings (diagramming software) and Google Fusion Tables (database manager; experimental).

Supporting paragraphs: Xabber F-Droid
Answer: free and open-source software