Just to close the loop here on a response I already gave on IRC: The unfortunate problem is that Rocket.Chat's API (and mobile app) has moved forward since 2017, but unfortunately, the Sandstorm package has not. (Presumably, if you had a copy of the mobile app from 2017, it might work though!) There were a couple attempts to get it up to date, but nobody ever moved it to publishing an actual new release. We currently have some issues packaging Meteor apps as well, so unfortunately, I'm not sure I expect us to tackle that one particularly soon either.