Los Angeles-based Burstly, the mobile ad management firm run by Evan Rifkin, said this week that it has added SoftBank Capital and Founder Collective to its Series A funding round. Size of the additional investment was not disclosed. Burstly recently announced a $1.8M investment from Rincon Venture Partners and GRP Partners. Rifkin was the founder of TagWorld/Flux, which he sold to MTVN in 2008. Burstly is developing a free ad management platform for the mobile phone market, and specifically the iPhone and Android operating systems.