Before I comment, I'll just express how insanely cool this is. Mobile programming environments suck right now and this is a step in the right direction. Good proof of concept.

Excuse me if this is implemented and just not in the README:

It would be super awesome if there was a type inference engine that fed into the UI to increase productivity.

For example, if I start to define a function that returns an int, when I go to write out the definition, it suggests functions to me that return ints.

Suppose I pick a function "string_length" which takes strings and returns ints. Now I continue the composition, so it suggests functions (either built-ins or user-defined) which return strings.

Suppose I pick "bool_to_string" which takes a bool and returns strings. Then to finish off the function I pick from a list of bool-returning functions, say I pick "xor".

So now with a few keypresses I have defined a function that, in C, would look like:

    int foo(bool x, bool y) {
        return string_length(bool_to_string(x ^ y));
    }