Ask Lemmy

A bit more niche, is Weasis - Dicom Browser for medical images. Alternative is also ImageJ which is used a lot in for scans too.

Wikipedia. Not an app but still deserves a mention.

I still can't get used to calling programs apps

OBS, and Blender. Two industry shaping software solutions that ere fully open source and free.

Librewolf, FFmpeg, Vim, Wine

The Dialer.

• Comes with every phone
• 10+ digit number instantly connects you with millions of people, services, and institutions
• 3 digits connects you with life-saving emergency support
• Very low-latency voice support
• High quality audio (most of the time)
• No ads
• No obnoxious UI

All kidding aside, I'm routinely astounded at how we have yet to top the ease and utility of old-fashioned phone service.

uBlock Origin leading the pack by at least a furlong.

Home Assistant, not only an App but it changed the way i look at IoT/Smarthome and in that way it brings me a lot of comfort.

KiCad. GNU Linux. Blender. Gqrx. Rclone. Syncthing

Organic Maps. After switching to graphene, I quickly found plenty of apps replacing the "defaults" I had on stock android, however, a good app for maps was impossible to find until I stumbled over that one. Great UI, local maps, even has a navigation feature. Completely replaces google maps for me.

Signal. Highly secure communication. No ads. Easy to use.

Linux

7 zip, VLC, Paint.net, proxmox, home assistant

LocalSend, Immich, Signal, Aurora store, Radio Garden, Gray Jay, yt-dlp, and Bitwarden just to name a few

YouTube clients like NewPipe

Proton. Literally makes any of the big linuxes into the streamos people are waiting for

VLC is a big one for me.

Libre Office

New pipe, I didn't see anyone mentioned it

Besides, I use Linux, Organic maps, Signal, VLC, KDE on daily basis and THANK YOU good people on internet for making my life happier!

Wikipedia

Get outta here you Hedge Fund Manager! Leave our apps alone!!

Blender, Gimp, Inkscape, OBS (open broadcast software), Linux distros of various sorts, openHAB, LibreOffice, Firefox (and plugins like uBlock), PiHole, VirtualBox, Notepad++, Paint.NET, VLC, 7-Zip, FileZilla…

I’m sure there’s more.

Blender

Fucking entire Fedivere with No ads.

Can't believe no one has mentioned Home Assistant. Automation engine for home and have local control over almost everything "smart" at home.

Jellyfin.

firefox

considering the big monopoly of chrome based is not really free, it's paid by google or microsoft mining user data

7zip

Practically every single FOSS application I use is highly useful to me, and of course, free, so I'll just list them all here.

• Immich - A full-featured replacement for Google Photos, has a sleek UI, face detection, albums, a timeline, etc.
• Paperless-ngx - Document management system, saves me a ton of paper hoarding, and makes everything easily searchable with OCR.
• Syncthing - Simple file synchronization between my devices, on my terms. Doesn't share data with big tech companies about my files, and hooks up extremely fast P2P connections that beat cloud-based services by a long shot.
• Metube & Seal - Simple interfaces for downloading with yt-dlp, can download from YouTube, but also many other sites. Doesn't spam you with popup ads or junk redirects like those "youtube downloader" type sites. Seal is my favorite of the two, but is only on Android.
• Image Toolbox - Insanely feature-packed app for doing practically anything you could want to an image. Converting formats, clearing EXIF data, removing backgrounds, feature-packed editing, OCR, convert to SVG, create color palettes, converting PDFs to images, decode and encode Base64 to and from images, extract frames from gifs, encrypt & decrypt files, make zip files, and a lot more. All local.
• Rustdesk - No-nonsense remote desktop, tons of features, simple file transfer, cross-platform compatibility, and P2P communication without needing a third party server if you so choose.
• LibreOffice - Essentially everything you'd get with Office 365 (e.g. Word, Excel, PowerPoint) but without the $150 price point. Compatible with the same file formats, and has the same functionality.
• Cashew - Feature rich financial app for budgeting, tracking purchases, saving for goals, etc. Doesn't have automatic import, but I find that manually putting every transaction in keeps me aware of my spending much better than before, so for me it's quite worth it. Install directly from the APK, or use on web though. The version on the app stores has some features locked behind a paywall.
• Linkwarden - Bookmark manager with cross-platform support, a web interface, automatic tagging, automatic archiving of any saved links in multiple formats, collaborative sharing capabilities, and more. It's free, but you can also pay $3/mo if you want them to host it for you.

Edit: And Umbrel (on Raspberry Pi) if you want to host things more easily. Basically just a much more hands-off, user-friendly docker for people who don't want to tinker as much.

Edit 2: Non-FOSS, but Obsidian is the best note taking app I've ever used. Great selection of community-made plugins (which are FOSS) for additional functionality, and all notes are in standard cross-software-compatible Markdown. No locked-in proprietary formats.

Godot

I cant believe it has a better user experience than unity, an app that has a 412 USD/month paid plan

Adding the following that i have not seen mentioned yet:

Docker - I literally run most of my server programs with docker now. Home Assistant, Jellyfin, and many others.

Tiny Media Manager that I use to scraper and organize my media library

Tiny Tiny RSS to combine my news sites into one aggregator. I actually saw this post on it since Lemmy has RSS feeds!

Openwrt I run as my home router.

I2P but it's still pretty clunky.

Nomachine I use as a remote desktop client.

RocketDock I still use on my windows desktop after windows removed the programs toolbar.

ImageJ/Fiji I use for image processing, it's from the NIH, with a bunch of Java plugins.

Gluetun I use to run my vpn client

Kodi for multimedia

OrganicMaps, all the trails I've been to so far in the US are available for offline navigation. No need to precache via gmaps and pray it won't get deleted

Edit: OpenStreetMap which powers this is what AllTrails uses, but I'm not sure if they contribute back or not

systemd

Krita. I had a uni licence for Photoshop for years, even took a Photoshop course but still kept using Krita. It has an intuitive UI and all the tools I'll ever need.

RStudio+R is way better than any of its proprietary alternatives.

Blender. I'm no 3D modling expert but it does everything I as a hobbyist want to do with it and so much more. Nowadays, the UI is pretty decent, too.

Finally, the Lagrange browser is really good. The gemini protocol is kinda niche though, but if you're interested it's unreasonably pretty, well optimized and has a great UX. The guy who maintains it really puts his heart and soul into it.

Organic Maps

Watch duty

AntennaPod

Signal

Shattered Pixel Dungeon

Voyager.

Vim. Every computer I've owned since the early 1990s has had some version of Vi on it.

Linux.

At least $100 per system, if not more.

ZFS

I think Blender is a very honorable mention, especially since the team that makes the software has also used it to make some really impressive short films, such as Big Buck Bunny. Who knows, maybe some indie studio can use it to make some truly wonderful stuff (and I wouldn't be surprised if that was the case).