Here are some resources to help you study English.
Dictionary.com app
A full English dictionary in your pocket!
http://dictionary.reference.com/apps
Google Translate app
Useful for single words.
https://play.google.com/store/apps/details?id=com.google.android.apps.translate
https://itunes.apple.com/sa/app/google-translate/id414706506?mt=8
Oxford Picture Dictionary
For sale in bookstores.