Most people really cannot tell you what they want in any reasonable way. So expecting good specs for software without a very laborious interview and review process is pure wishful thinking. People "know what they like when they see it", so spend time rapid prototyping.
Smaller and more recent: iTerm has deep tmux support. Just do `tmux -CC` to start your session or `tmux -CC a` to attach to it and you don't have to memorise all the tmux commands.
Also half of those people will "tell" you what you need to build and you need to work backwards from there to figure out what their actual problem is before working forward again to figure out what you actually need to build.
Dealing with this at work right now. A newly promoted lead is struggling to delegate and all of the work coming out of his team right now is instructions on how to do what they believe they want. Very frustrating!
Smaller and more recent: iTerm has deep tmux support. Just do `tmux -CC` to start your session or `tmux -CC a` to attach to it and you don't have to memorise all the tmux commands.