MkvToolNix has been really useful for me, mainly just for trimming videos and removing surplus language tracks/subtiltes without having to reencode

Syncthing: Continuous, private, and encrypted file synchronization across multiple devices without using the cloud.

KDE Connect: An app for iOS, android, pretty much every flavor of linux, windows, etc. that lets you connect any devices together to share files, show notifications of other devices, use your phone as an input device(keyboard, mouse), control multimedia applications(start, play, stop, etc.), trigger commands, and everything else if you make a plugin for it.

KeePassXC: A modern, secure, open-source password manager that stores and manages sensitive information offline.

LocalSend should be called God Send because it'll save your life. It's AirDrop, but for everything and open source. Works really well, no setup, no server.

Forgejo: A self-hosted, lightweight software forge offering Git repository hosting with an easy-to-install, low-maintenance platform focused on collaboration, federation, and privacy.

Lichess: A popular free, open-source online chess platform offering play, puzzles, and tournaments.

Newpipe, an YouTube client, which is:

• ad free

• lightweight

• useful, it allows downloading videos, music, and playing them when screen is locked

• usable without account

• multi-platform, it can also serve as client for the PeerTube, Bandcamp, SoundCloud

LibRedirect is an open-source browser extension for Firefox and Microsoft Edge that automatically redirects popular online services like YouTube, Twitter, Instagram, TikTok, Reddit, and others to privacy-friendly alternative websites, enhancing user privacy by avoiding trackers and data collection on the original platforms.

Rustdesk.

It's TeamViewer / AnyDesk without the headaches.

Joplin: An open-source note-taking and to-do app with markdown support and end-to-end encryption.

Anki (and AnkiDroid):

The gods of learning and studying with flashcards. You will never want another flashcard program, especially if you were still using Quizlet (so enshittified now...) because Anki uses SRS (spaced repetition system) which makes you review things right before your brain forgets it to reinforce the subject material.

Add-ons: Bread and butter of Anki, I use several to make beautiful automatic flashcards of reading material/videos/games when I study Japanese. There's an add-on for literally anything.

Cross platform: Free on desktop, cost $25 on iOS, and free on Android, although Ankidroid is an unofficial app. Still great though!

Cloud: Syncs your anki database across devices. If you don't use anki for a while, will delete from the cloud, but as long as you have your own local database intact, you can reupload again later. (EDIT: Went through settings, you can self-host your own sync server!)

Sharing Decks: If you don't feel like making your own decks, download ones that others shared for free.

Anki is used by language learners, college students, med students, etc. If you need to memorize it, use Anki.

tmux: A terminal multiplexer that enables managing multiple terminal sessions within a single window, allowing detaching and reattaching sessions to keep programs running in the background.

Pandoc: A universal document converter allowing conversion among numerous markup formats including Markdown, LaTeX, HTML, and Word.

OsmAnd, mobile app for navigation and maps. Offline, based on OSM, can do anything. I use it for checking out and bookmarking places, finding POIs and pubic transport stations, routing (especially for bike and foot), measuring distances, and so on. It can also show and record tracks, do car navigation, edit OSM points, and more stuff that I don't use. Pro/plus/full version free on FDroid

Zotero: a free and open-source reference management software to manage bibliographic data and related research materials, such as PDF and ePUB files.

Immich is a photo/video hosting solution à la Google photos

Shattered pixel dungeon. Open source dungeob crawler roguelike. Extremely fun.

Typst: A modern typesetting system designed for easy document creation with markup inspired by Markdown but more powerful and programmable.

rnote Rnote is an open-source vector-based drawing app for sketching, handwritten notes and to annotate documents and pictures. It is targeted at students, teachers and those who own a drawing tablet and provides features like Pdf and picture import and export, an infinite canvas and an adaptive UI for big and small screens.

FairEmail, email app for Android that has every feature I can imagine. Available on FDroid

qBittorrent: only for your legal torrenting needs from e.g. archive.org :>

Lemmy ^[1]^

LibreOffice - simply the best office suite there is (IMHO). I was a MS-office user for years, but since I switched, I haven't looked back...

This post is a gold mine!

librewolf a privacy-focused fork of the latest stable firefox (win,linux,mac)

Calibre: great e-book manager

Copyparty turns almost any device into a file server with resumable uploads/downloads using any web browser

PieFed: a link aggregator and forum platform built for the Fediverse, focusing on individual control, safety, decentralized power, and healthy community interactions, with features like reputation indicators and keyword filters to enhance user experience.

Inkscape - the best vector graphics program out there. So easy to use, and so powerful.

Czkawka: A free, fast, and open-source tool for finding and removing duplicate files, cleaning empty folders, and optimizing storage by content-based file comparison across multiple platforms.

screen

a gnu until that let's you run a persistent session, even if you log off. log back in and reattach your screen and whatever you were doing is still running.

VLC (VideoLAN media player): play media files, DVDs, network streams and more. Just works,

Tenacity - a pre-enshitification fork of Audacity. An audio recorder and editor that does multi-track recording, effects and much more in a really simple UI.

Krita is a fantastic program for drawing. It's made for making beautiful paintings and animations.

GIMP - unlike Krita - which is made for drawing - this is made for photo-editing. It's like Photoshop. The learning curve is a bit steep, but it is really powerful.

Flameshot: screenshotting tool with everything you would ever need for screenshots

Firefox - the original private webbrowser. Even though some people don't like the options in it (like those that let you stream Netflix and other DRM content). If people care about privacy, they use this browser, or one that is made from it...

Xournal++: A C++ handwriting note-taking software with PDF annotation support.

Nicotine+: A lightweight, free, and open-source graphical client for the Soulseek peer-to-peer file-sharing network.

Helix Editor: A fast, post-modern text editor that combines modal editing and syntax awareness built in Rust for programmers.

Thunderbird - a brilliant e-mail program, which also handles contacts, newsfeeds, calender and more. It's available for multiple platforms, like Android, Windows, Linux and so forth...

Mullvad vpn, probably the best vpn imo

strudel. From the website:

With Strudel, you can expressively write dynamic music pieces.

The best place to actually make music with Strudel is the Strudel REPL

It's really fun to make music in it, I recommend trying it out!

link to repo (codeberg)

Nuclear: A free, open-source music player that streams content from multiple free sources like YouTube, SoundCloud, and Bandcamp without ads or subscriptions.

emacs, the text editor. it's so powerful and customizable that I feel listing any feature would do so many others a disservice

Audiobookshelf. Not exactly a "hidden" gem at this point, but I'm putting it here for today's lucky 10,000. Simply the best way to store and stream audiobooks. Does podcasts too, and ebooks, although there are better tools for those.

Comaps, navigation from openstreetmap