Best language learning tool?

[frostmane]

Which App Store application do you think is the best language learning tool on iphone? There're too many of these kind of tools.
I found an application named Surfiar, this one makes it possible to look up and save words when you are surfing internet or viewing text file without quiting your present reading. I think this may be time saving.
Anyone introduce me any other tool please?

 

[TheAppencyPress]

This is only for Spanish, but the Memorize Words - Spanish app is really great. Has lots of words, games, and knows when you are going to forget something somehow, so it reminds you!

 

[frostmane]

Thank you!