Here is a excellent tip submitted by Lisa, I have never seen the name brand of cooktop cleaner in my area but I will definitely look for it based on Lisa recommendation.
I clean houses for a living, and the best way to clean a glass cooktop is to purchase a bottle of Weiman Glass Cooktop Cleaner. Squirt a generous amount onto the cooktop and spread around with a wet paper towel then wipe off with a dry paper towel until the cooktop shines. For cooked on stains, VERY CAREFULLY use a paring knife or other knife with a sharp, straight edge held almost parallel to the surface to scrape the residue from the surface before removing the cleaner with the dry paper towel. You may have to use more cleaner or wipe it away and reapply it to get everything. This works extremely well, and I have had clients ask me how I get their cooktop so clean.