I have been learning french on and off for years and know a lot of vocab and the basics but was lazy with grammar and sentence structure. I have done a fair few apps and podcasts but Rocket French is the best I have used for building structure in all areas. I love it and would recommend it. It is interestijng , well paced and covers a wide range of topics and phrases.
Areas for improvement - As per a lot of other reviews, I can't use the speach areas on my laptop as it doesn't pick them up well (it's better with headphones but still not great) however it works fine on my phone so I just use that for speach.
Other niggle is that the French pronounciation of the American presenter/ introducer is so awful. The two french role players are understandably great but I'm suprised Rocket French used someone who pronounces so many french words and phrases so badly. It's less of an issue as you then hear the french role players covering it in the role play so you hear how it should be said but it is poor someone who does not have good pronounciation has been used for a good quality paying product - which overall all Rocket French absolutely is.