Smartphone holster - fully customizable

Where you do keep your phone when on the move?
Without thinking, you probably either hold it (especially indoors) or tuck it in one of your pockets. Only to find it awkward when you sit down or need to get your keys, ID, bank card or money. So, more often than not, as soon as you sit down, you put your phone on the table, desk or chair near you. Where it is then sometimes forgotten when you stand up. Looking for your phone is something everyone seems to do every day.
This behaviour has become so automatic that most people don't even think about it.

However, there is a simple solution.
With this parametric holster, designed in OpenSCAD, you can 3D print a holster specifically for your smartphone. I have been carrying my phones in this way in total comfort and without the need to worry about it for over two years now and have printed many for others as well.
It is convenient and comfortable, in your chair, the car, on your bike or walking.

On the inside of the holster, a layer