Update: 4/6 4:17 p.m. ET: Twitter's development team has announced it will delay an API that could cause third-party Twitter applications to lose some critical functionality. Specifics on timing were not announced, but Twitter said developers will get 90 days notice, and is inviting developers to apply for beta access. The original story appears below.
In June, third-party Twitter clients like Tweetbot, Talon, Twitterific and Tweetings may lose crucial features like push notifications and the ability to auto refresh, say the makers of those apps
On June 19, Twitter is poised to replace its "streaming services," which power those features on third-party clients, with a new Account Activity API.
That new API is in beta testing, but the creators point out on a protest website, Apps of a Feather, that no outside developers have been invited to test it. While they speculate they may be able to fix push notifications, it sounds like real-time updates are at a dead end.
"There is no web server on your mobile device or desktop computer that Twitter can contact with updates," they wrote. "Since updating your timeline with other methods is rate-limited by Twitter, you will see delays in real-time updates during sporting events and breaking news."
In some cases, this dramatically reduces the number of available options. For example, on macOS, Twitter discontinued its own native Twitter application in March, and third-party clients are popular alternatives for power users who didn't want to use the website. They also often offer more features. For instance, I use Tweetbot on Mac and iOS, and I can sync my timelines, mute tweets by keywords and, frankly, I prefer its interface.
Former Twitter product director Jeff Seibert took to, well, Twitter to call the lack of communication with developers a "grave error" that would "effectively end Mac support."