For years, I have used and loved the Franklin-Larousse electronic French<>English & French<>French dictionaries. The electronic dictionary was superb, but I had hoped that someday, I would have a version on my phone so that I would have one less thing to carry around in my pocket on my visits to France. Now I have it on my Android phone and I love it.
It has 250,000 words and phrases and 400,000 translations. It also has a verb conjugator and pronunciations, and it only costs $6.99 (far cheaper than the $50 - $100 I’ve paid for the separate electronic versions). This version does not have the French<>French dictionary.
For French dictionaries, pronunciations are very important because French, like English, uses an ambiguous writing system. (The pronunciations are only available when there is Internet access.)
One of the great things about this dictionary is that it has lots of contextual examples.
Some might thing that 250,000 words is an absurd number. However, I’ve found that dictionaries that only have 10,000-20,000 words are inadequate because you often cannot find the words you need once you get beyond the most basic level.
You have to be careful when buying this app because there is another Larousse French<>English dictionary app which sells for the same price, but has 80,000 words.