can you write a program that opens a text file and dumps its contents on STDOUT? then you can write `cat`! and there are oodles of tools that are as simple as that.

the nice thing about contributing to a busybox-like distribution of coreutils is that they intentionally leave out the bells and whistles, since the target systems are memory-constrained. and you can do the development and testing right on your workstation. busybox is designed to be suitable for embedded devices, but the tools will run on any device with a linux kernel, as long as you can compile for the target CPU.