Traditional Chinese IME on Android is a 20% IME project initiated in Google’s Taipei office. This project is based on Android input method framework, and like LatinIME, its codebase is kept small, readable, and open sourced under an Apache license on Google Code. It includes Zhuyin and Cangjie, two dominant input methods for Traditional Chinese users. People interested in building new input method, see how ZhuyinIME and CangjieIME extend AbstractIME and create their respective Editor and WordDictionary subclasses to compose Traditional Chinese characters. We’re currently working on two features: How to support English suggestions without duplicating LatinIME data, and How to map Zhuyin’s 41 keys onto the QWERTY 26-key layout for hardware keyboard,” noted Google.
More info: Traditional Chinese IME on Android