You want to test your English grammar knowledge, try this App.

Lern the German alphabet with this game. More information can be found at: http://www.vocaword.org

Improve your english with english study

Kudos Wiktionary Word of the day APP and WIDGET.

Learn a new word everday by either launching the app or including a widget on your home screen (To add a widget after installing the app tap on an empty part of your background and select 'widgets' then 'Wiktionary')
Tapping the widget will give a full explanation of the word.

Dictionary data taken from wiktionary.com
Parts of the source are taken from or modified versions of that found on the Android Developer Blog.

The only offline English-Catalan dictionary for Android. More than 33.000 words!

Geiriadur Saesneg-Cymraeg a Cymraeg-Saesneg.
The only Offline English-Welsh Dictionary for Android! More than 14.900 words! FREE!

edicpopAND help read and listening.

A rich source of words for everyone who loves language, this free dictionary is both comprehensive and authoritative with its 123,000 words and 200,000 definitions based on the Collins Word Web - an unrivaled and constantly updated 2.5 billion-word database of today's English.

Offline English Arabic dictionary.
قاموس عربي إنجليزي
More than 83.400 words. FREE!

GoDic is one of the best dictionaries and translator for Android. English, German, Italian, and 40 other languages are available using GoDic. Translate English, Spanish, French into more than 40 languages. And all this functionality without an Internet connection except the initial download.

DEX for Android is an online and offline Romanian explanatory dictionary - Dictionar Explicativ Roman - (http://dexonline.ro).

http://dex.adrianvintu.com

Commands Dictionary is an android application which has been built for getting quick reference to commands required for AIX admin,DBA i.e Database Administration as well as SAN which stands for Storage Area Network.It also includes UNIX as well as TSM commands which are helpful for AIX,DBA and SAN.This application gives a short decsription of these commands which can be quite useful to Core IT people.

Offline English Russian Dictionary. Англо-Русский словарь
More than 69.500 words. FREE!

Convenient app to use the multitran.ru online dictionary.

Offline English-Basque and Basque-English Dictionary. More than 9.000 words. FREE!

Offline Spanish German dictionary. Spanisch Deutsch Wörterbuch Diccionario español-alemán
More than 42.000 words! FREE!

Offline German Italian Dictionary. Dizionario Tedesco Italiano. Deutsch Italienisch Wörterbuch.
More than 32.000 words!

Offline French-German and German-French Dictionary.
Französisch-Deutsch und Deutsch-Französisch Wörterbuch.
Dictionnaire Français-Allemand et Allemand-Français.
More than 30.000 words! FREE!

Offline English Hindi Dictionary. More than 27.400 words. FREE!

Ultimate online dictionary with Wiki app for android 1.6+ Fully supports Moto Droid & Nexus 1. Can't find in dictionary? Find it on Wiki Wiki Wiki!

Features:
Droid & Nexus One Support
Text to Speech Keywords
Dictionary & Wiki as backup!
Dictionary Words Update Online
Dictionary find closest match
Now with THESAURUS!