I just recently got one of these:
3D Tempered Glass Screen Protectors For Iphone 6 Plus 6s Plus By DBPOWER, Stainless Steel Edge, 3D Curve fit, 0.15MM, 9H Tempered Glass, HD Clear[3D Touch Compatible]-Black
https://www.amazon.co.uk/dp/B019ZJE7XM/ref=cm_sw_r_cp_awd_JJa9wb49YAGKE
For my 6 +. While it is a steel surround with just the screen area being glass. It's the single best (of literally dozens I've tried) one I've had for coverage. It's really thin, it actually does completely cover the screen, including going round the curved edges. I'm really pleased with it.