ProCode is a tiny 0.1M and downloaded in like 1 second to my iPad, and ran without incident. The app is a pretty basic calculator, sans scientific or any advanced functions (like memory, % function, square root, etc.). The only addition is the conversion features, which transposes the values you enter in the source field (upon which calculations are exercised), into converted output in the target field (decimal, binary, hexadecimal, or octal).
Well, that's it. Nothing fancy here, just a calculator that converts to various base systems of measure, so if you aren't in need of any heavy duty binary output, you can move along now. A couple things I think the developer might do to make his $1.99 app a little more interesting. Add other geek-related conversions (disk storage, RAID, subnet calc, etc.). I would make the app free and maybe throw some ads on it, create some customizable themes or something. That way people can use it for free, and the coder can get something out of the deal as well. Maybe update it and make the graphics fully iPad capable. Just some thoughts. If you are looking for a hard core calculator that only does base conversions, check out ProCode here.