Hindi English Dictionary This is surely the best Shabdkosh-Hindi English dictionary for Android. Only works online. Easily searched.
English to Hindi Translator This free app translates English words and phrases into Hindi. Works offline! Great for communicating and learning simple phrases.
Hindi Flashcards Learn how to read Devanagari letters with these flash cards. Free. The pronunciation is not great.
Hindi Dialog For .99 you can have a decent Hindi phrasebook on your phone. It has sound and text and you can enter English in for Hindi translation as well.
L-Lingo Learn Hindi Free Ver. This is the best learning app for Hindi hands down. This free trial will help you choose whether it's worth $14.99 to you to learn Hindi. Audio, pictures, text, fun learning tools. Very useful!