I wanted to vertically place my iPad in its Logitech folio touch (or similar) case on my desk, so it won’t take much space. I also wanted it to not need much filament, so I just made this. It’s far from perfect, so feel free to improve, but for me it gets the job done. I placed some soft pads inside, so the iPad won’t fall out easily. The stand itself will be glued to my desk using doublesided adhesive tape. 
 

the space in between the holding parts is 24mm.