SAN JOSE, Calif. (CN) — The executive chairman and co-founder of a live-video and mobile messaging app was charged and pleaded guilty Monday to felony tax evasion. The felony tax evasion charge generally applies for amounts greater than $3.5 million in tax loss. Immediately after his appearance, a second hearing with U.S. District Judge Noel Wise included a change of plea from not guilty to guilty. The Tango app is a social media platform that streams short, live videos from creators to audiences worldwide, and was valued at over $1 billion in 2016. Raz stepped down as CEO of the company in 2016 but remained at the company as executive chairman.