Granboard Smartphone Holder Granboard Smartphone Holder. The smartphone holder can be used to attach smartphones to the gran pole stand using the clip. It can be attached to older model, GRAN POLE STAND or both new versions. You can easily attach this holder and use the touchscreen of your smartphone during matches. There’s now no need for a table or a resting place for your phone to fall or slide off of. Easily mount it for viewing and smooth out your transition between shots!