I’m both happy to see it and annoyed at myself for sitting on another good idea.
I feel your pain – I had a great idea for a website about 1999/2000 but the technology wasn’t there then to make it work – this was back when home internet was slow dialup, then there was the dot.com crash, then I went travelling, and left the industry entirely never to go back. So I was happy / annoyed a few years later when my idea came to fruition and someone else launched something that was pretty much exactly what I’d envisaged. Slightly more annoyed than happy for the founders when they sold it for $1.65 billion.
YouTube
I have no particular problem with the whip round app, but it does appear to be a solution in search of a problem.