As of Friday afternoon, the so-called input method apps, which serve as virtual keyboards, could not be downloaded on Chinese Apple iOS store and Android app stores operated by Chinese smartphone makers such as Huawei.
Iflytek said in a statement that the app was removed due to violations of personal data collection rules, and it already completed the "rectification" and was currently waiting for approval from the regulators.
Sougou didn't immediately respond to a request for comment.
In April, China issued draft guidelines seeking to limit the scope of mobile apps' collection of personal data.
Apps in China have been temporarily removed by regulators for mishandling user data or improper content, with existing users unaffected.
(Reporting by Yingzhi Yang and Ryan Woo in Beijing; Additional reporting by Pei Li in Hong Kong; Editing by Elaine Hardcastle)