March 22 (Reuters) - U.S. mobile app and gaming company AppLovin Corp, backed by private equity firm KKR & Co Inc , is looking to raise as much as $1 billion through an initial public offering in the United States, according to a regulatory filing. Reuters reported in October that AppLovin had hired Morgan Stanley to lead the IPO, citing people familiar with the matter. reut.rs/3scQITi (Reporting by Sohini Podder in Bengaluru; Editing by Sriraj Kalluvila)