There are many interactive grammar sites found on the web. One which I have used with many classes from Primary through to Seniors is www.quia.com.
Activities on this site are written by teachers for their classes and for others to use.
Once you have logged on to this site, click on the yellow circle "Try it Today" then click on French. This will take you to a variety of drop down box options.
If you decide to use this site with your class make sure you have identified the exact activity/activities so your students do not waste time searching for relevant topics. I suggest that you give a choice of 5 to 10 sites for your students to choose from during a lesson.
Joining Quia allows you to create your own activities using their own templates.