IMPORTANT: You must select "Update Dictionary" from the menu after installation. The download is large (~20 megs) so do it over wifi.
Search the dictionary by inputting Chinese character. You can also use yale punctuation with tone numbers but the dictionary is really meant for Chinese -> Engilsh lookup so this mode may not work well.
There is no built-in IME. Please install an appropriate Chinese Language Input Method into your Android device separately.
Dictionary data is taken from Cantofish with permission of the author. It also includes some other data published on the Cantodict forums.