Traccar - a GPS tracker.

It tracks devices around on a map and records stats about them. Used by fleet managers to monitor thousands of vehicles simultaneous, and also people like me with just two. The interface is a little quirky, but otherwise it’s a very solid and capable program. It shows a web map with live positions of the devices, battery state, speed, direction and other datapoints.

My wife and I like to know where the other is because we both do dangerous shit solo. (She horseriding, me motorbiking, and we’ve both got health conditions). I get notifications when she enters any number of geofences, and can see where she is at any time - and vice versa. This has eased anxiety for both of us.

Initially we used Life360 which is a nice and easy app to use. Then we found out that they sell your information to actively work against you. Not just basic stuff for advertising, but your driving habits, speed, style, accelleration rates - to car insurance companies so they can raise your policy costs, or potentially deny your claim entirely. (Just one reference but there’s heaps more)

So we went self-hosted. Traccar is free and I keep our information private. Install a small app on your phone and register it, and done. Or it integrates with dozens of commercial and open source tracking systems.

Disclaimer - not involved with the project, just a user and a fan.

(Just noticed my wife’s left her phone behind when she went off riding… I guess no system’s perfect!)

PlantNet

It identifies the species of the plant in a given photo.

• 7-zip
• VLC
• Signal
• Currency
• Handbrake
• Fennec (in lieu of Firefox)

Those are the free ones I use very frequently at least, I’m sure there’s more.

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

OctoPrint for 3D printing

Retroarch.

God awful complexity but once you figure out how it all works it’s incredible.

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.

VSCode. I don’t get why Microsoft hasn’t monetized it but I’m glad it is free. Has so many extensions and gets great updates, even if I don’t understand half of the stuff in their patch notes when I open up the program.

Another one is a little program called Stacher that basically serves as GUI for yt-dlp. It’s a very pretty one though! And all the settings and buttons are super great. I’m not very good with CLI stuff so I’m glad it exists for free, saves so much time.

for windows:

• WizTree - Disk space visualizer
• Everything (& EverythingToolbar) - Search tool
• Playnite - Game library

for android:

• Mihon/Tachiyomi - Manga reader
• Obtanium - Manage apps from various sources (github, gitlab, etc)
• Syncthing-Fork - File syncing
• MiXplorer - Feature dense file manager
• Universal Android Debloater Next Generation (technically a windows/linux program) - Remove/disable stock apps

for linux:

• wine/proton - windows translation software
• yazi - File manager
• easyeffects - Audio processing
• mpv - Video player

Wikipedia. Not an app but still deserves a mention.

WinRAR

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.

Jellyfin.

Off the top of my head:

Krita

Handbrake

LibreOffice

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.