I actually made the first version if this program a long time ago, before I became active in the community. I remade it a few nights ago and uploaded it to TICalc, but it basically works like this:

-Give it a list of coordinates and types
-It generates a hex opcode that draws the rectangles with the given coordinates and methods.

It takes input in the form of {x,y,width,height,type} and you can give it multiple rectangles. It does 6 rectangle types, including the typical black/white/invert, using OS bcalls. This is also a BASIC program that generates the opcodes. As well, it tries to optimise the opcode a little, so if there are 8 or more rectangles, it uses a different method of drawing them (generating an array of coordinates/types and reading them, using 29 bytes extra overhead, 4 bytes less for each rectangle).

Anyways, it was useful for me when I was working on BASIC RPGs to make an assembly program that drew a map. The download is below. With so many other tools available now, this type of program is a bit outdated

It is actually slower than most libraries (I am sure I can make a library slower, though ). However, it doesn't have any dependencies, and for anybody that can't send apps or programs to their calc, they can just open this BASIC program in Source Coder 3 or something and copy it onto their calc and be able to use customised assembly code for their games.

As well, it has no dependencies other than it needs to have the TI-OS or something compatible.