Mobile/iPad stand

I need something that positions the mobile phone upright, makes it easy to read WhatsApp messages. It allows the phone to be charged while in use too.

I've tried creating some 'holes' into the design (to save on material used.) But, printing it horizontally, the holes weaken the structure and the object tends to crack/break easily. So, just a small hole for the charging cable.

The tilt angle is 30 degrees from the vertical. I find this angle is most comfortable for viewing.