I remember the first time I experienced this was an iOS app called Task Eater. It was simple To-dos. Attractive, snappy, everything you could need. The dev released a "final update" where he basically declared it was done. This was pretty early iOS (iPhone 4 era?).

The only problem is he never updated it to roll forward to future iOS version/iPhone models and it hasn't been usable for years (and years).

This made me search it up - the world moves so fast it's difficult to find any information on it whatsoever.