Cookie Words is a mobile application that lets non-native speakers
see in 1 second (and with zero interruption) the definition of words
they don't know while reading content on their mobile device.
Looking up words on one's mobile device can be a maddening
experience - Switching to a dictionary site/app, looking up the word,
and then coming back takes at least 20~30 seconds PER WORD
and makes it almost impossible to focus on what you're reading.
Just highlight and "Copy" any word and the definition will be pushed
to you at the top of the screen. And every word you look up is saved
in the app for future reference, creating a "word timeline" that allows
you to better track your improvement in that language over time.
http://cookiewords.com