update: after years of refusing to do so, their dev team apparently figured out how to run some basic commands to wrap an official client. Good job, your team managed accomplish what a incompetent student did in a day. Well done. If you read this, don't get Asana. IMHO it's shit.
Nothing fancy, just a simple nativefier build and some instructions how to do it from scratch.
Download it for MacOS or Windows.
There are Manual Build Instructions with an easy walktrough availible, in case you are new to node, npm and/or nativefier. They are basically the code and documentation in case you want to know whats actually in the binaries.