This listing collects a set of Free Software Applications as replacements and alternatives to default Android applications which are proprietary (nonfree) software.
Adblock (uBlock Origin), Clock (free/TimerDroid), App Center (F-Droid), Book Reader (Document Viewer), Calculator (F-Droid), Calendar (Etar/Fossify/Simple Calendar Pro), Contact (Fossify), Compass, Camera (Libre Camera), Chrome (Fennec/Thorium), Drive (Fennec/Thorium/Nextcloud), Download Manager (Download Navi), Gallery (LeafPic/Camera Roll), Google Search alternatives (DuckDuckGo/Startpage/Setter), Hangouts (Telegram FOSS/Conversations/Element/Simple X Jami), Home Launcher (KISS Launcher), Keyboard (Simple Keyboard), Music Player (Music or VLC), Mail (K-9/Delta Chat), Maps (OpenMultiMaps/OsmAnd), Messages (Silence/Simple SMS Messenger/Fossify SMS Messenger), Meet alternatives (Telegram FOSS/Element/Jitsi Meet/Jami), Notes (My Notes), Scanner (QR Scanner from SECUSO), YouTube alternatives (NewPipe/Clipious), and VLC for Videos.
Proprietary software is completely owned and controlled by its developer, rather than the user. Free software alternatives exist because proprietary software often invades privacy and is seen as unjust, and free software is fun to contribute to.