TextSecure (text) and Redphone (voice) were the precursors to Signal in 2011 through to 2014. The Whatsapp purchase by facebook happened in 2014.

But the first official release of Signal was June 2014 (which was just the merger of Redphone and textsecure)

*All from Wikipedia correlations and faulty memory :D

I had meant I switched when the news of the new access to data request started last year.