RenDaKid

I've been resource gathering for YEARS so now I am going to share my dragons hoard

Floorplanner. Design and furnish a house for you to use for having a consistent background in your comic or anything! Free, you need an account, easy to use, and you can save multiple houses.

Comparing Heights. Input the heights of characters to see what the different is between them. Great for keeping consistency. Free.

Magma. Draw online with friends in real time. Great for practice or hanging out. Free, paid plan available, account preferred.

Smithsonian Open Access. Loads of free images. Free.

SketchDaily. Lots of pose references, massive library, is set on a timer so you can practice quick figure drawing. Free.

SculptGL. A sculpting tool which I am yet to master, but you should be able to make whatever 3d object you like with it. free.

Pexels. Free stock images. And the search engine is actually pretty good at pulling up what you want.

Figurosity. Great pose references, diverse body types, lots of "how to draw" videos directly on the site, the models are 3d and you can rotate the angle, but you can't make custom poses or edit body proportions. Free, account option, paid plans available.

Line of Action. More drawing references, this one also has a focus on expressions, hands/feet, animals, landscapes. Free.

Animal Photo. You pose a 3d skull model and select an animal species, and they give you a bunch of photo references for that animal at that angle. Super handy. Free.