Doesn't affect existing apps with extended mode access, for which you have to apply and be approved. Gives you a higher ratelimit so you can ship to production. Plenty of people (me included) build small widgets for themselves without bothering to apply for extended.
> Most people writing small scripts were probably using an API key with development mode.
Yep, me included. Since my apps were never meant as anything more than utilities for myself, I never applied for extended access. Nevertheless, I used these tools multiple times a day, especially for sorting and filtering playlists by audio features such as energy and valence. Now, apparently, they will never work again. I'm sure there are plenty of other hobbyists in the same boat.
Even for those that want extended access, what's suppose to be a simple review process is absolutely broken. Their dev forum is full of people who have applied and been left waiting for months with no communication.
Not OP, but also used the API for music discovery, crawling the related artists network from playlists I'd created to find highly connected nodes. I found that strategy was very efficient at filling blind spots in major genres I listened to, and reasonably good at exploring random niches, but generally wasn't the place I found songs that felt truly fresh to me. It felt like it got noticeably worse about 5 years ago, when I perceived them to have ramped up the payola, but that might just be in my head.
