Ok first off don't get all excited about the version 4 folder just yet! It's incredibly unstable and won't work for you just yet, version 2 and 3 are fine to use from this location (may actually decide to serve them from here long term as it allows for better update control)
So you just have to visit https://wavemakercards.github.io to be able to access the running versions
I am currently working on version 4 which is built using Vue - and will include Electron standalone installers - this is in the /dev folder (ignore the v4dev one - I need to kill that)