Blender is a legend of open source software, a full suite of 3D tools for modeling, rigging, animating, rendering, on and on. I know the basics for pulling together some renders but there's unlimited potential if you dive into it.

Lately I've been getting more into building maps, and QGIS has been a blessing. The interface is pretty dated and unintuitive, but I don't really mind with how much it's opened up my horizons. Here's me reskinning some OpenStreetMap data.

One cool one app is Darkroom. It simplifies file management because it just works like a RAW photo editor on top of Apple Photos. You can delete, tag, flag, reject, and manage photos, and it all just syncs. You can even save edits as a non-destructive version on top of your RAW photos.