Its maybe not cheap, but its good - I reckon its worth the coin...very easy/fast to get to what you need, no internet required and generally easy on the eye. Ive completely abandoned my paper French-English dictionary for this; I use it every day.
Works fine on an iPhone, but with the bigger real estate of an iPad its very nice to use.
If you consider the 100s of hours youll spend studying french, why would you want some pos toy app for $0.99?
Symbol 45 about Collins-Robert Concise, v2.4.2