Discuss and learn French: French vocabulary, French grammar, French culture etc.
The truth is that many language courses like the ones you mention are more like glorified phrase books. Most learners simply don't get very deeply into grammar, and so most mainstream language courses don't go overboard on grammar.
The thing you need to find is what resources are right for you: for different people these will be different things.
What level have you reached so far, would you say? For example, are you comfortable with the basics of determining what verb form to use where? Or are you still looking for grammar a bit more basic than that?
With a few reservations, there's a book Correct your French blunders (link is to a review I wrote a couple of years ago), which offers some "medium level" grammar and vocab information in a fairly "pragmatic" way. That means it doesn't go into very very advanced topics, and like many typical textbooks aimed partly at school exam takers sometimes tells slight white lies for the sake of giving a rule that will work "much of the time". But it does pack quite a lot of material in and as I say is quite good if you want a fairly "no nonsense" explanation of points even if linguists looking for more technical information will cringe slightly at some of the content.
You might also want to see this site's grammar section: http://www.french-linguistics.co.uk/grammar/
If you've reached the level yet, try and listen to some French news such as the free programs available on France 24, look for magazines in French on your favourite topics...
And you might also want to ask whatever questions you have here on the forum-- that's what it's there for!