I originally wrote this suggesting a feature of using the .app vsn number for the directory name when install from branches like @master.
I've decided thats not a good way to go and would prefer to simply be able to clone an entire agner "repo" (more than 1 application per git repo).
I know that goes against Agner's design essentially. The agner_index behaviour doesn't feel generic since its based on git tags, branches and repos... But I will attempt to add this alternative index idea.