I've seen folk doing these little lists of tools they use. I like reading them. I figure I'd join in for funsies.

Software:

• VSCodium; An open-source alternative to VSCode
• Obsidian; Writing app. I use it for basic notes/to-do-lists
• Krita; Open-source drawing software
• blender; An open-source 3D modeling software
• LibreOffice; An open-source alternative to Microsoft Office
• Aseprite; A drawing software for creating pixel-art. Cost 20 clams, but there is a free, open-source fork called LibreSprite

Game Development:

• LÖVE; A cute little framework for developing 2D games in Lua
• Godot; An open-source 2D/3D game engine
• Twine; An open-source writing software for interactive fiction
• PICO-8; A "fantasy console" for making retro video games. Cost 15 doubloons, but there's also an education version one can use for free.
• bitsy; An editor to make small games

As you can see, most of this stuff is free and open-source. I try to use as much open-source software as possible, because I like supporting these endeavors.

Have fun.