Bulbul Apps, a Hyderabad-based early childhood learning app developer for pre-schoolers, has announced raising Rs 3.5 crore of funds in a fresh round from Xseed Partners, Operator VC, Anblicks and Infoblob. Bulbul Apps had raised seed capital of $200k and another $1m earlier. Focussing so far on the Indian market, the education startup is now looking to expand into the US market. It plans to deploy the latest round funds to build B2B2C market that was showing promising growth in the number of paid parents and subscribers.