Here is a short list.
Pc: Cachyos(Preformant linux distro based on arch),Cinnamon (fork of Gnome 3),Librewolf (web browser)
Android phone:F-Droid(Appstore),Clipious(YouTube client but network is nonfree),aurora store(replaced Google play store with this and network nonfree),Iceraven (Web browser,Can be hardened as much as mull.),
Cross platform: Localsend(Airdrop for any device),Vlc media player
Yeah that's it,here is my major apps I use

On my laptop:

• Void Linux
• GNOME (desktop environment)
• gThumb (image viewer that can do simple edits)
• Firefox (the famous web browser)
  • uBlock Origin (content blocker that blocks ads, trackers, etc. out of the box)
  • SponsorBlock (automatically skips sponsor segments in YouTube videos)
• Betterbird (fork of the Thunderbird email client, with various QoL tweaks)
• GIMP (image editor)
• Kdenlive (video editor)
• virt-manager (manage QEMU virtual machines)
• Celluloid (media player)
• yt-dlp (command-line utility for downloading YouTube videos, and the basis of some graphical apps as well)
• Bottles (if you want to use Wine to run Windows apps, without too many headaches)
• Foliate (.epub ebook reader)
• OBS (for screen recording and livestreaming)
• Code - OSS (code editor, "clean" version of Visual Studio Code without "Microsoft-specific customizations")
• Tenacity (fork of the Audacity audio editor without opt-out telemetry)

On my Android phone:

• F-Droid (app store with FOSS apps only)
• Obtainium (auto-updater for apps hosted on GitHub, GitLab, etc.)
• Heliboard (simple keyboard app)
• Material Files (file manager)
• Metro (local music library player)
• Iceraven (Firefox fork with a few tweaks)
• Voyager (mobile client for Lemmy, similar to the obsolete Reddit clients Apollo and Slide)
• Fedilab (client for Mastodon and similar Fediverse services)
• Termux (run Linux CLI applications on Android)
• Thunderbird for Android (simple email client for Android and the successor to K-9 Mail)
• MJ PDF Reader
• Binary Eye (simple QR code scanner)

Cross-platform:

• LocalSend (simple file transfer between devices on the same network)
• Bitwarden client apps (to manage passwords. I use the Vaultwarden instance @ tchncs.de)
• Mullvad VPN client

If we can count FOSS modifications of proprietary apps:

• YouTube Revanced (the official YouTube app, but you don't get ads, you can play videos in the background, you get SponsorBlock, etc.) (follow this guide for auto-updates)
• Vesktop (desktop client for Discord, has Vencord preinstalled and supports Linux screen sharing)
• Prism Launcher (Minecraft: Java Edition launcher that allows you to easily manage different "instances" of the game. Good for playing with different mods and/or versions)
• Fabulously Optimized (modpack for Minecraft: Java Edition, that improves performance and adds some minor QoL features)

addendum: I'd like to use Matrix (via the Element client) and Signal more, but most of the people I know are on Discord and WhatsApp instead.

Matrix (element on mobile, cinny on pc), materialious (linux app for invidious, alternative yt frontend), gzdoom (foss engine for doom & mods), luanti (a minecraft-like engine for playing minigames and shit), zen browser (firefox fork with a pretty skin), xfce as desktop environment, wine for playing windows games

On my mobile with GrapheneOS:

• Aard 2 (dictionary, since QuickDic doesn't seem to work on my Pixel 7)
• Breezy Weather
• Fossify Suite (Calendar, Clock, Contacts, Gallery, Messages, Notes)
• Currencies
• DAVx5 (calendar sync)
• Feeder (RSS)
• FUTO keyboard
• Hypatia (malware scanner)
• Island (work profile enabler)
• K-9 Mail
• KeePassDX
• Molly (Signal fork)
• Music Player
• Nextcloud
• Obtainium (update apps from source)
• Oeffi (public transport)
• OSMAnd
• Planisphere
• StreetComplete
• Threema Libre
• Tor
• Tusky (Mastodon)
• Vanadium (GOS Browser)
• Voyager (Lemmy)
• Who Bird (bird call identifier)

More FOSS apps on my notebooks with Fedora, but not on a daily basis.

Oh boy! Here goes

Desktop:

• Bazzite
• KDE Connect
• KiCAD
• FreeCAD
• Plasma
• LocalSend
• Thunderbird
• Bitwarden
• Code OSS
• Krita
• CoreCTRL
• LibreOffice
• CuteCOM
• KopiaUI
• Calibre
• Heroic Games Launcher
• Lutris
• PrusaSlicer
• Okular
• Inkscape
• FluffyChat
• SyncThingy
• Elisa
• Haruna
• Kdenlive
• YouTube Downloader GUI
• Paperwork (stille can't get network scanners working on Bazzite with sane set up)
• Solar
• ProtonUp-QT

Phone:

• AntennaPod
• Immich
• Aegis
• Heliboard
• Organic Maps
• Breezy Weather
• Aurora Droid
• K9 mail
• Signal
• Fluffy chat
• Home Assistant
• Eternity
• Findroid
• Gadgetbridge
• Fitotrack
• Loop habits
• Tuta
• StreetComplete
• Wireguard
• Unit converter untimate
• mastodon
• ntfy
• newpipe
• KDE Connect
• bitwarden
• findroid
• localsend
• material files

server:

• Leantime
• Bookstack
• Immich
• Jellyfin
• Home Assistant
• Traefik
• Crowdsec
• Authelia
• Dozzle
• Glances
• full *arr suite
• transmission + wireguard
• paperless-ngx
• cloudflare-ddns
• syncthing
• valheim server
• Boinc
• stash
• ntfy.sh

If I donated $5 per month to each of these projects I would be broke 😂

On Android :

• ⭐Kvaesisto launcher
• ⭐Acode
• Blichess
• ⭐Brave browser
• ⭐Cuscon
• Data monitor
• Drip
• Droidify
• ⭐ FetchIt
• Right files
• ⭐ Right messages
• Fossify gallery
• Libchecker
• ⭐Linkora
• Inkwell keyboard
• Obtainium
• ⭐Octogram
• Oincoin
• ⭐PocketPal
• ⭐Proton VPN
• ⭐Quillpad
• ⭐Record You
• Simply translate
• ⭐Termux
• ⭐Thunder
• ⭐Tubular
• VLC
• ⭐Windscribe VPN
• Warden
• Zcalc
• I also used to use apps like Anytime podcast , Focus podcast , Book's story , Hacki for hacker news , Rain , Weather master , Heliboard (I'll reuse it again because inkwell and florisboard still don't support typing suggestions) and other apps I can't remember right now

I made my own curated list of open source software. Most of the software on there is stuff I use.

I use GVIM everyday.

I frequently use CentOS because that is what the embedded system I work on runs.

I use cygwin regularly professionally and at home. Identifying specific software within it is tough, but I definitely use grep and g++ all of the time.

deleted by creator

A lot.

Desktop/Laptop

• Artix Linux
• Neovim
• BSPWM
• Suckless Terminal
• Librewolf
• Firefox
• Ungoogled Chromium
• Thunderbird
• mpv
• rtorrent
• Keepassxc
• btop (TUI resource monitor)
• links (old school TUI browser)
• newsboat (TUI RSS reader)
• yt-dlp
• git
• Espanso (text expander)
• GIMP
• Inkscape
• Krita
• Calibre (for epubs, great with Kobo ereader)
• Wireshark
• Lutris/WINE/Proton
• OBS

Phone

• Android/GrapheneOS
• Heliboard
• FUTO Voice (Speech to Text)
• Mull
• Vanadium
• Various Fossify Apps
• Keepassxc
• Thunder
• Tusky
• Thunderbird
• Tubular
• Seal (yt-dlp wrapper)
• mpv
• Antennapod
• Feeder (RSS reader)
• Glider (HN client)
• OSMand
• Stealth (Reddit lurking)
• Element (Matrix client)
• Transistor
• Translate You
• Protonmail
• Proton Drive
• Breezy Weather
• URLCheck
• Wikipedia (official reader)

My most used:

• self hosted Matrix server with Element client
• Jellyfin server and clients
• self hosted Radicale server for my family calendars
• self hosted Joplin server with the Joplin app on all my machines and devices for my notes
• Navidrome
• Firefox
• tasks.org with my self hosted nextcloud
• all the fossify apps on my phone
• audiobookshelf server and client
• GNU/Linux (various distros across different machines)
• Voyager for Lemmy

There's a bunch more that I can't think of that I use, but the above list is the stuff I rely on and use every day.

Android Custom ROM itself

-Adaway -App Manager -Audile -Audio Recorder -Aurora Store -BiglyBT -BitmaskVPN -Bitwarden -Calyx VPN -Capy Reader -Cromite -De-Bloater (i translated it to hungarian) -easyNotes -eduVPN -Eternity -F-droid -Android Files -Android Recorder -FlorisBoard -Android FM Radio -freeDictionary (Owl) (i also translated the menu to hungarian) -FTPClient -FUTO Keyboard -Gadgetbridge -Android Gallery -Android Game Space -HeliBoard -Human Benchmark -Breezy Weather -Image Tools -Invizible Pro -Jerboa -Lagrange -LavSeeker -Magisk -microG -Namida Music Player -Fossify Calendar -Fossify Contacts -Next Player -Obtainium -OCR -Odyssee -OnionShare -OpenCamera -OpenVideoEditor -Android Clock -Forkgram -Organic Maps -Orion Viewer -OSS Document Scanner -Pachli -QR Scanner -Racoon -Revenge Discord Client -Root verifier -SD Maid -Seal -Setter -Shitter -SlimSocial -Spotube -StrongSwanVPN -NumberHub Calculator (i also translated this to hungarian) -Fossify Phone -Termux -Thunder -TranslateYou -UPnP Explorer -Fossify Messages -Vernet -ViperFX Material UI -Voyager -Warden -WikiReader -Xtra

And this is only my phone...

On android, I guess, it's smth like: heliboard, mull, eternity, tubular (a newpipe fork), antennapod, feeder, simplex, element and slightly patched mercurygram.

As for the desktop, Firefox, keepassxc, anyrun (the app launcher) and cosmic-term would probably be the GUI apps I use most often; occasionally neovide if I feel like drooling on those sick cursor animations, mpv if I want to watch stuff without distractions, or kicad if I'm into making some electronics-related pet project. Other than that, my workflow is mostly terminal-centric, so the fish shell, coreutils, neovim, moreutils -- mostly vidir for visual bulk renaming and vipe for editing piped stuff in place (for one-time things that require, say, >2 seds) --, and so on.

on android it's RiMusic, Thunderbird, Firefox, Feeder, Breezy Weather, Showly OSS, PipePipe, and Simple Keyboard. all available on f-droid

On android, GrapheneOS, AntennaPod and Tempo are probably my top ones. On my desktop, Firefox, tmux, mpd, ncmpcpp, gonic, neomutt, qbittorrent, weechat, mc, btop, Lagrange and emacs probably round things out for me outside of base OS stuff. OS side, my desktop has Arch Linux and my laptop runs OpenBSD. Bitwarden across platforms.