Underwaterworld Keyboard Theme is a free personalization app developed by 2018 Kika Cool Theme for Android. This app is exclusively designed for Android 9.0 and provides users with a variety of features to personalize their Android device. With this theme, you can change your background, fonts, sounds, and use funny emojis and kaomojis. Autocorrect and next word prediction features are also included to enhance your typing experience.

The app supports over 150 languages and provides a clipboard for multiple fast copy and paste. Users can also swipe to type and choose from 6000+ colorful themes or customize their own. The app is compatible with almost all Android phones, including Samsung Galaxy, Sony Xperia, Huawei, HTC, OPPO, Xiaomi, Nokia, VIVO, and Moto. The app promises not to collect personal information and only uses the words typed by users to enhance predictions.

Overall, Underwaterworld Keyboard Theme is a great app for anyone looking to personalize their Android device and enhance their typing experience with a variety of features and themes.