Instant messaging

Columns: Instant messenger client | Company | Usage
BlackBerry Messenger | BlackBerry | 91 million total users ( October 2014 ) | Hike Messenger | Hike Messenger | 70 million active users ( October 2015 ) | Gadu-Gadu | GG Network S.A | 6.5 million users active daily ( majority in Poland ) ( June 2010 ) | IBM Sametime | IBM Corp | 20 million users ( February 2006 ) | ICQ | ICQ LLC | 11 million total users ( July 2014 ) | IMVU | IMVU , inc | 1 million users ( June 2007 ) | Paltalk | Paltalk.com | 5.5 million monthly unique users ( August 2013 ) | Signal | Signal Foundation | XMPP ( Protocol used by multiple clients ) | XMPP Standards Foundation | 1200+ million ( September 2011 )

Example questions:
Who was cofounder of the other platforms instant messenger that had 1 million users in June 2007 ? | Which platforms is the desktop version of the other platforms instant messenger that had 5.5 million monthly unique users in August 2013 available on ? | Which company acquired the other platforms instant messenger that had 11 million total users in July 2014 ? | Which South African company owns the other platforms instant messenger that is popular in Poland ? | What kind of software is the other platforms instant messenger that had 20 million users in February 2006 ?

Answers:
Eric Ries | macOS and Windows | Mail.Ru | Naspers | middleware