A giant list of older games re-implemented or made to work natively on Linux with Luxtorpeda (a steam compatibility tool, nicely selectable from within Steam itself).

Compatibility layer here: https://github.com/luxtorpeda-dev/luxtorpeda

Play Gothic 2 on modern systems with ease! Open source reimplementation of the game engine.

Open-source smartwatch that is fully arduino programmable (run by an ESP32), usually lasts 5-7 days and costs around $50.

Quite a few watchface examples exist online. From what I understand, the watchface is the firmware for this clock,
so no too easy changes there.

There are assembly kits with a case that can be bought for some $ more that will keep the watch a bit more safe (though not e.g. swimmingpool ready). The watch/display so far only exists in square shape.

Alternative firmware for ESP8266 with easy configuration using webUI, OTA updates, automation using timers or rules, expandability and entirely local control over MQTT, HTTP, Serial or KNX. Full documentation at - GitHub - arendst/Tasmota: Alternative firmware for ESP8266 with easy configuration using webUI, OTA updates, automation using timers or rules, expandability and entirely local control over MQTT, HTTP, Serial or KNX.

Brilliant short explanation of the difference between the three popular FOSS (/OSS) licenses.
Boiling it down to 'what are you afraid of' really helps quick decision-making.

Simple, efficient and pretty.
A minimal GUI Journaling application - it gets out of your way and allows you to write in markdown.

One neat feature is its calendar view which lists the quick titles of your journal entries for days passed and thus gives you an overview of what you did when and when you were journaling.

If you need a terminal equivalent use jrnl instead.

A free and cloudless replacement for your gadget vendors' closed source Android applications. See the list for supported devices. https://gadgetbridge.org

Many many Linux softwares. Mostly useful as an overview for someone looking for a software in a specific area of computing (audio engineering, writing, database editing, programming, ..) since they are nicely sorted and allow an overview of FOSS alternatives to various software needs.

Mimcs photoshop a little more - especially in layout and shortcuts - by changing GIMP settings around.
Also installs a ton of fonts by default.

Minimal interface styling for Firefox - contains only the tab bar on top, with the address bar shaping up when you move the cursor close (or Ctrl-L I suppose).

Looks neat if you're using FF

Amazing pre-setup mopidy and snapcast instance. Simply point your docker-compose file digestor at it and you're basically good to go with iris and spotify integration running (though you have to enter your credentials into .conf file for spotify to fully work). Then begin populating the music folder and you have your local music added.

A list of programs that are built on* vim concepts, predominantly hjkl movement and modes.

• built on can mean fully supporting, intended to replicate, mimic, provide configuration for, up to and including be configurable enough, I believe.

How to Self Host Matrix, an open source project that publishes the Matrix open standard for secure, decentralised, real-time communication.

Good explanation and simple steps. Federation can be tested here: https://federationtester.matrix.org/

Super small operating system (for x86) - couple of megabyte disk and around 8MB RAM and you're off.
Contains games, a simple text editor, table editor, image viewer, and some more.

Open source, experimental, and tiny tools roundup.
Mainly themed around creation, graphically, such as generative art, games and word play.

Contains lots of nice little tools, some of which are truly not famous yet.

LineageOS with any google play services replaced by the open-source microG framework

Allows developing raw (and other) formatted photos, mimicks lightroom and carries similar editing capabilities.
Good library management.

Raw file editing software, mimicking lightroom or darktable for editing capabilities with fewer library features.

Nice markdown notes management / writing app.

Simple interface, reminiscent of old Evernote clients - but targeted plainly toward plaintext note-taking.

Good explanation of the very basics of open source software principles.