I am a native English speaker, but am fairly fluent in French. I find the dictionary accessed by this App to be excellent. It is clear, informative and rich. I prefer this dictionary to my Petit Robert. The App is also well done. I very much like that if you hold your finger down on a word in a definition, up pops a button for a search on that word. The history function is also quite useful. The App is responsive and quick, but it depends on having connectivity. If it were not for this (usually minor) drawback, Dictionnaire would easily be 5 stars in my book.
andyfu about Dictionnaire de français TLFi, v1.6.1