I think it was actually just a straight mobile clone as I see "WigglyPaint" in the screenshots and the original Android app was called WigglyPaint as well based on the url (/apps/details?id=io.wigglypaint.android). Probably got more popular than they were expecting and decided to pivot a bit.
Sorry to hear that. It seems to be working fine based on the couple hundred others that have signed up this evening, so maybe try again? If that doesn't work, hit me up via email (listed in my profile) and I'll see what I can do!
Thanks for mentioning Hacker Newsletter! I hear from several subscribers a week (currently have almost 40k) that mention it has helped them cure/control their HN addiction. :)