Roost App Reaches 300,000 Users Five Weeks After Viral Threads Post

Roost, a mobile app that sends messages at the flight speed of chosen birds, reached about 300,000 users roughly five weeks after a mother posted on Threads that her daughter was using it to communicate in Elizabethan English. TechCrunch reported that the app grew from 10,000 to 100,000 users within three days of that post.

Logan Mendelsohn, a senior product manager in trust and safety at Ticketmaster, began building Roost as a side project for use with friends.

Friends encouraged him to publish it to the App Store, TechCrunch reported. By default the app shares only a user’s city, with an optional close-friends setting for precise location that must be enabled manually. The Pen Pals feature allows exchanges with anonymous users in the same age group.

Users receive warnings during onboarding not to share contact information or personal details. Mendelsohn has not added photo sharing because he wants to implement additional content-moderation tools first. Mendelsohn used Claude Code to assist development.

He has no outside funding and generates revenue only from in-app purchases such as extra birds. He is running an artist contest to replace AI-generated bird images with human-created art. Mendelsohn told TechCrunch that users value the slower pace.

“Everything on a phone is instantaneous these days,” he said.