PhahTaigi 台語輸入法 (Taigi Keyboard) is a free, open-source application developed by Tâi-bûn Ke-sī-mī for Android devices. It allows users to conveniently write in Taiwanese using their mobile phones. The app supports both the Pe̍h-ōe-jī and the education ministry's Han characters and pinyin systems.

The app provides users with a list of suggested words based on the input, which makes it easier to write in Taiwanese. The words are arranged based on the order of the tones, and the app also supports multi-syllable words with one or more tones. Users can even type in the first letter of a multi-syllable word and the app will suggest the full word. The app also includes a dictionary that includes words from the Taiwan-Japanese dictionary and the education ministry's Taiwanese dictionary.