Bought for use with iPad 2. Cheap product and initially pleased with it. However, at the weekend when using the stylus, it caused a deep scratch in my (thankfully) protected screen. The reason for this is that although the tip is very soft and safe, the metal collar around it is poorly machined and had a very rough edge. This means when using the stylus on the screen, if you are using the stylus at a writing angle, the collar will touch the screen and, if you are using a screen protector, will scratch it. I don't know if it would mark an unprotected iPad screen but would not want to try.
I am now left with a big scratch right in the middle of my iPad screen protector and will either have to get a new one (for £13) or live with it. The stylus is in the bin where I feel it belongs.