Ooh, good timing to stumble on this thread, wanted a place to dump this on. Been fiddling around with some homebrew stuff, on the flashcard for my old DS-Lite. Found this quite amazing little painting app (Colors), that has a legit color-wheel and one heck of a good photo-shop-like brush tool. And what I never expected that old DS to be able to do, is that it actually supports pressure sensitivity. It also saves a timelapse of your entire work (wich you can pause at any time, and go back to draw at that point in time again, instead of an undo feature, wich you only have 1 step of).
And it lets you export the painting in a PNG at suprisingly high resolutions.
I doodled some Pokemon with it, while experimenting with the brush and it's settings, trying to get some lighting and shading going on, after randomly starting out, drawing a gradient background and some glowy white orb in the middle.
By no means, impressive for a digital painting, but think it's pretty amazing to be able to make this, just on an old DS-Lite. (funnily enough, a way newer 2DS-XL's touchscreen does not support the pressure sensitivity).