Innovative designed and fully centralized under your (admin) control. Server (PHP) provides great flexibility, including the 3rd-Party extension possibility (e.g. forum, CMS, blog, PGI, CRM...). Allows companies/communities (organizations, associations, institutions...) and dispersed workgroups to create and control their own network of instant collaborative messengers (your own private or public WhatsApp).
Can install server on your local network (lan) or on internet (a shared hosted server is enough).
NEW: Users Files Backup: create your own dropbox/SkyDrive/hubic/...