[doiwin]

I would like to code WebAssembly by hand. Are there any good tools / tutorials on this?

[lj3]

Do you mean something like this? https://mbebenita.github.io/WasmExplorer/

[kodablah]

Probably not any good tools or tutorials, but the wast format is not that hard [0][1] and most compilers accept that format. Just gotta keep the values on the stack in mind while you write.

0 - http://webassembly.org/docs/text-format/

1 - https://webassembly.github.io/spec/text/index.html