I've never bought an app that was one-star, but over time many of the really useful apps I used were sold and did one-star kinds of things.
One app kept track of my car info (vin, insurance, mileage, fillups) and was useful. But one day it was sold - uploaded my data and put it behind a login.
"[but] did one-star kinds of things." That is a great line (seriously). I will probably end up working that phrase into something at one point, which is why I have this post bookmarked, so I can "hat tip to m463 on HN" when I do.
P.S. Do you remember the name of that auto app? Name and shame! ;-)
Another app I had that got worse was camscanner - a scanner app that would take a picture of a document and create a .pdf out of it.
It was sold to tencent. The "privacy policy" - when you could access it (broken links) was written in broken english that basically said it did anything it wanted with your .pdf files.
The kinds of documents I would image to .pdf were extremely sensitive personal documents - think w2, documents with SSN, etc...
At least apple notes eventually added a version of camera to .pdf (though it wasn't obvious how to use it when it came out)
Camscanner was one of my favourite apps! I had even paid for the pro version back before it sold. Then when it sold that actually meant nothing, and now I have a "pro" app that is useless essentially.
If anyone has good alternative suggestions I'm open, I haven't tried to look as I don't use it much anymore.
Maybe these are apps with bad user interfaces or some other issue and it's a list of low hanging fruit ideas?