Learn Words Language Helper

Maximum Efficiency Language Trainer. Start by memorizing words from most frequently used ones downwards. After 500 of those vocabulary start reading more sample sentences to get an intuition for the grammar - even before learning any explicit rules.
Next learn some grammar rules the traditional way and then watch soap operas at half speed with subtitles in the foreign langauge. Make sure to use the internet in the foreign langauge at this stage whenever you look something up.
This app focuses on steps one and two.  

You can enter your own terms into this advanced learning app. 
Custom crafted learning-modes get you up to speed in no time! Get a score of your exam performance! 
The product is self-explanatory.

Subscription terms:
http://czokindustries.com/get/subscriptionTerms.pdf

While the main features of the app are always free to use, you can get access to some additional features by purchasing a premium subscription:
The free trial brings no commitment and can be cancelled any time. No cost is incurred for the free trial.
Any unused portion of a free trial period, if offered, will be forfeited when the user purchases a subscription (if applicable).
Duration of Subscription (after the free trial): One Month, or two Months, or one Year, depending on your choise.
Price per Month (if the free trial is not cancelled): Around the equivalent of 4 USD per month. Prices may vary by currency and the option chosen. 
Subscriptions auto-renew unless cancelled 24 hours before renewal. 
Payments are deducted from the users iTunes Account at confirmation of purchase.
Subscriptions can be managed in the Account Settings.

Terms of service and privacy policy: 
http://czokindustries.com/get/privacyPolicy.pdf