Ranked in these QuestionsQuestion Ranking
Pro Cross-platform desktop, mobile and web
There is iOS, Android, Mac, Windows, Linux and web software available.
Pro Multiple service integrations
Hall integrates with Dropbox, Box, Asana, Trello, Github, Heroku, Jenkins, New Relic, Pivotal Tracker, UserVoice and Zendesk.
Free on on all devices.
Pro Dropbox and Box integration
You can use Dropbox and Box to share files in Hall.
Con Has gone out of service
But may be integrated into Atlassian's HipChat.