I made a Brainfk interpreter a little while ago in Ti-BASIC, but it was slow and lacked a good UI.
So, over the past few days, I've been working on a Brainfk interpreter using AXE, which I call BrainfAX.
It has a built-in program editor:

In the editor, you can add the selected character to the program with [2nd], and scroll through the options with the arrow keys. Pressing clear saves the program and goes back to the main menu.
It has a nice way to view the programs running:

Left and right arrow keys are used to scroll across the numbers, while the top row of buttons has four things to control: Restart, Input, Single Step, and Auto
It can be found here: https://www.cemetech.net/downloads/files/2894/x3861

Also, what are the programs stored as? Appvars? Strings? Did ya use MEMKIT?
Also, did you imply that it can run multiple programs?

I just stored it in an AXE var, and it just works somehow. It will erase the program with a RAM clear though, and I think if you use another program it will too... The saving capabilities are very limited. Maybe sometime I will improve it.
And for now, no it cannot run multiple programs

Well, I'd definitely use an Appvar, if it's like that then there's no garuntee that it'll last. Definitely switch to Appvars, man.