A8.com, which mainly sells ringtones and other digital music to mobile phone subscribers in China, has filed for an initial public offering on the Hong Kong exchange to raise about $28 million (217 million Hong Kong dollars), reports China Web 2.0 Review. The company, which was founded in China in 2000, has raised two rounds of financing previously from IDGVC, TDF, Intel (NSDQ: INTC) Capital and JAFCO. The company sells ringtones, ringback tones, mobile games and other digital content to subscribers of China Mobile and China Unicom.