This API suits Twitters goal of feeding analytics and entertainment products, but it's a heavy blow to developers of third-part Twitter apps like Twitterrific and Tweetbot, and services like the already shutting down Favstar. Here's why:

So, to start with, third-party clients will have to discontinue features like live updates and activity information. Developers at The Iconfactory, which created the first-ever third-party Twitter Client, Twitterrific, have been sharing their reactions:

Make it $14 or more once associated costs are added and implemented, which would be untenable.

It's possible Twitter will work with developers to come up with affordable alternatives and even feature workarounds. There are no guarantees, though. And the bigger problem remains: Twitter, for years now, has through action and innaction been terrorizing the developers that helped make the service popular in the very early days of the service.

Favstar has already announced it's shutting down due to the uncertainty and constraints Twitter continues to introduce.

August 16, 2018 is the new end-of-life date for the old Streaming API. We'll have to wait and see how many third-party apps and services it takes along with it.