Christmastime is here, and Khush is celebrating the season with the launch of Singing Santa. The interactive iPhone application features an animated Kris Kringle who belts out user-customized musical messages set to the melody of popular holiday songs, all optimized for sharing via Facebook, Twitter and email. Singing Santa is Khush's first animated character app, following on the heels of hit music creation solutions LaDiDa and Songify. Its release isn't all the company is celebrating this December: Khush made headlines earlier this month when it announced its acquisition by Smule, the pioneering mobile app maker behind music-themed blockbusters including Magic Piano, Ocarina, I Am T-Pain and MadPad. FierceDeveloper spoke to Khush co-founder and CEO Prerna Gupta about Singing Santa, the Smule deal and building an audience.