As you may remember, ADI was an experiment on the part of Europress to educate above the Fun School age, reaching into secondary education, ADI Maths and ADI English were both excellently received, and so ADI now adds French to its repertoire. Using the same system of varied questions and mnemonics, ADI works more towards helping children remember French words and phrases, rather than try to teach them from scratch.
For example, instead of giving you a list of new phrases to learn, ADI revises what you should have already been taught, by asking you to fill in missing words or answering simple queries. For example, when should you use the prefix 'Ille' as opposed to 'Elles'.
The presentation is, as always, excellent with the character of ADI constantly present in the top left corner. As you improve, he will drop in the occasional word of praise, get something wrong, and he will remind you that you can ask for help at any time. In that sense, ADI takes over the role of the teacher, leaving the more difficult problems to be solved in the classroom.
I would have loved something like this when I was learning French, aged 11. It really does help your understanding of the language by letting you experiment with it, much the same way that you would were you speaking it to a native. Not entirely essential, but for most it is a vital learning aid.