here’s some stuff I can offer for the list:
Medibang Paint Pro has a lot of similarities to SAI but it also has some nice bonus resources and works on various devices + it’s completely free:
Font Squirrel is a website that collects free for commercial use fonts, meaning you can find a fancy font for that set you wanna make and not give any money for it:
(still, always read the license agreement, just in case)
There’s some very cheap fonts as well, in case you want to buy a font, but don’t feel like paying a ton
While on the subject of buying resources, Sellfy offers a lot of textures, fonts and other designer goodies that you can use in your sets and most of them come at reasonable prices
There’s also monthly bundles that help you get more stuff for less money as well as friday freebies which only ask for you to share the product on social media.
DF drawing is a fun little twitter I have been following for a while, posts themed imagery for reference and inspiration, as well as tutorials found around the web.
They also often promote korean artists (which if you’re interested in anime styled art will probably bring some extra inspiration to your table) and boost accounts that offer anime related products.
in the same fashion, rare cabbage posts themed groups of images on their twitter, which can make for good reference or inspiration as well as occasional artist shares, but they also post texts quite a lot, which can get tiring if you decide to scroll down the wall and not just use the media window instead xD
Red Rabbit is a pixel artist I adore and they have made a few tutorials in the past on how they create their work.
Seeing as pixel art is really liked on NM, here’s a link to RR’s tumblr with all their tutorials
That’s it from me for now