a sketchfab-based tool with low-poly scans of many animal skulls that are freely rotateable (useful for tracing or reference in of themselves). but also, once you've arranged the skull at a preferred angle, you can use the search bar at the very top to search for photos of whatever animal you type into the search box, which will all be roughly facing the direction you have the skull facing! very handy.
i normally tend to avoid mobile apps that aren't open-source, but i needed a powerful drawing program specifically for my Android phone and this one ended up being the only mobile art program powerful and featureful enough to have everything i wanted. previously a different program was featured here, but this one i like better than the previous. this is also a program you have to pay for to unlock all its features, but is generally worth it in my opinion and does have a free version with limited features as well as a trial with all features unlocked so you can see if you like it before you buy.
completely free, open-source, photoshop-like digital art program i use for all my art done on my laptop! and i mean "photoshop-like" in its absolutely massive amount of features and similar UI. i've used a lot of art programs over the years, including photoshop itself and clip studio, but krita remains by far my favorite. runs on PC, Mac and Linux.
repository of 3D models, which you can buy or preview in your browser with WebGL. there are many anatomical references here, and the model preview allows for full rotation and zoom making them perfect reference / tracing material. this site has been absolutely vital to my continued understanding of human anatomy for art!
the best model of muscoskeletal structure on sketchfab i've found, hands down. 3D models are vastly more helpful to me personally than flat 2D reference materials, so this is my go-to for a refresher on the muscles and where they connect to the skeleton.
a comprehensive worldbuilding website for writers and RPG storytelling! i don't personally use this, but some of my writer friends swear by it.
i do take requests and suggestions for resources to add to this collection! send me a message on one of the accounts on my contact page. please be aware, though, ultimately i'll make my own final call on whether to add something or not. i intentionally leave out the very popular "industry standard" art programs because they're pretty easy to find, and in my experience none of them really deserve the huge amounts of praise they get -- there are much better and far less expensive alternatives out there that deserve a spotlight.
as with other link collections on my site, these websites are not affiliated with me or my own site in any way.