Dictan is an app for reading and viewing dictionaries. It supports both FDB and ZD format. You can add words directly from the Internet. 

Once you have installed the app, you can choose from over 400 dictionary and encyclopedia sources to find the information you need. From there, you can also make your own and share them with your friends. You can create a word list that includes all the words you want to learn. And when you go to school, you can check your word list to make sure you haven't forgotten anything.

Dictan is a dictionary app that is completely free and works on your phone.