Social media giant Twitter is facing backlash from users of some third-party apps. Popular third-party alternative Tweetbot pushed an update to its mobile app revealing that it would no longer have several key features after Twitter’s previously announced API changes. On Thursday, Twitter’s Rob Johnson tried to explain why the social network effectively killed off alternative apps, which led to more frustration from their users.

Johnson’s explanation came in the form of an email he sent to his team at Twitter, which he then tweeted out for the public to see. Twitter ended support for what it calls “legacy APIs,” or older tools that have allowed developers to use Twitter software for their own needs. In doing so, apps like Tweetbot lost their abilities to efficiently refresh timelines, send push notifications to users and provide other necessary features.

Johnson called it a “hard decision,” but said it had to be done since they were built on old technology and would only affect a small percentage of Twitter users.

The replies to Johnson’s tweet were not kind. Users of apps like Tweetbot pointed out that they preferred those apps because they had functionality that the official mobile Twitter apps do not. Whether they wanted additional functionality for their work or they just liked having access to those features, those users expressed their frustration towards Johnson.

“We feel the best Twitter experience we can provide today is through our owned and operated Twitter for iOS and Android apps, as well as desktop and mobile twitter.com,” Johnson wrote in a Thursday blog post. “We’ve long believed this — we’ve focused on delivering the best experience for our apps and sites for years.”

twet Twitter killed off key features of third party apps. The logo of social networking website 'Twitter' is displayed on a computer screen in London on September 11, 2013. Photo: Leon Neal/AFP/Getty Images

Either those users will migrate back to the official apps they do not like, or they will just leave Twitter. The site already took a stock hit after its latest earnings report revealed a drop in monthly active users.

Twitter killing off those developer tools is the latest instance of the site doing something to leave some of its users jaded. The company has received harsh criticism over the years for not doing enough to remove harassers and white supremacists from the platform. Though the site purged accounts belonging to people who had previously been banned, this week, it also controversially kept right-wing conspiracy theorist Alex Jones on Twitter while other prominent platforms banned him.