Amazing script. Thanks Kaspars. I got it working with some struggle. First I was not getting the slug on my server, so I had to hard-code it in the script. Then I changed the packages array to add lot more information so that it feels like the update is coming from the WordPress server (now it also generates that Details pop-up when a user clicks the link – get version x.x details).

Only thing I’m not able to figure out is the Upgrade Notice. Is there a way to get that working?