Dalton Caldwell and Bryan Berg announced the official shutdown of App.net today:
In May of 2014, App.net entered maintenance mode. At that time we made the difficult decision to put App.net into autopilot mode in an effort to preserve funds and to give it ample time to bake. Since then every dollar App.net has charged has gone towards paying for the hosting and services needed to keep the site running. Unfortunately, revenue has consistently diminished over the past 2+ years, and we have been unable to return the service to active development.
As I wrote about just last week, the founders of App.net deserve our thanks for trying something very difficult and succeeding beyond what anyone expected. I’m still amazed at everything they were able to do.
So, what now? I believe the next step for the open web and Twitter-like services is indie microblogging.