TS Big Keyboard [4Languages] is a free Android utility tool developed by TIME SPACE SYSTEM Co. Ltd. It is a multilingual keyboard that supports English, Chinese, Korean, and Japanese. The app comes with an input trace function that helps users find typos easily by showing which keys were pressed. The multi-toolbar feature allows for more convenient text editing, including a drag toolbar to move a cursor back and forth and a dictionary toolbar for entering text in Korean or English.

The app also supports one-hand mode for more comfortable typing and an artificial intelligence (AI) dictionary that suggests previously used words or sentences. TS Big Keyboard [4Languages] offers over 60 high-quality skins to customize the keyboard's appearance. Other features include emoticon input, autotext input, AI auto input, voice recognition, key height adjustment, and problem reporting. The app supports different input methods for Korea, Japan, and China. Overall, TS Big Keyboard [4Languages] is an intuitive and easy-to-use keyboard app that simplifies multilingual typing and offers a range of useful secondary tools.