A free program for Android, by NDT.

The Dictionary English Thai is an offline dictionary app for Android. It allows you to look up both English and Thai words. You can search words directly from “Internet Browser” or other Applications by using Sharing option. In the sharing option, you can find “Dictionary English Thai” in the list of your favorite Applications and click on it to share the dictionary with that application. You can also click on the “Add” button to add a word to the “Internet Browser” or another Applications. The dictionary has been designed to have a user-friendly interface. You can use either English or Thai keyboard to input the words. You can also change the default keyboard to use English – Thai keyboard.