Do you have decals or stickers on glass windows you cannot remove? This is quite common in kindergartens, schools, scout dens and even shops, check the windows on your van or car (check around your home too, it is amazing the things kids do).
The Blaster Wonder wheel can be your answer as it has been to people in many industries. As you know window glass is a very hard surface and does not mark or scratch easily. The wonder wheel will not damage or mark the glass as it is made from a specialised rubber and on glass very little pressure is required.
Almost any home handyman drill will hold the metal shaft of the Wonder wheel and you only need revs between 2000 and 4000 per minute and gentle pressure.
One of the great things about the Wonder wheel and folk sometimes don’t believe us until they use it, but due to the special composition of the Wonderwheel “rubber” it causes a very pleasant odour the same as caramel candy when being used. (Honestly it really does!). Light pressure is all that is needed on glass surfaces and generally on glass the Wonder wheel will also remove the adhesive
One must take care sometimes especially on marine craft and aircraft which sometimes use plexiglass instead of glass. Plexiglass is a form of clear or coloured plastic and scratches more than glass. Always test on an area out of sight or in where it will not be noticed.