I designed a case for the IPhone 5s/5c using Solidworks.
I chose the this design as I thought the combition of different curves created a pattern thta was interesting and unusual.
This case clips easily onto the phone protecting the back and the edge from scratches.
I designed it to be a a fast and easy print - placed flat down onto the print bed, so the file will print as it is - without any need for support material or any extra measures.
This case was printed using an Ultimaker 2.
I used white PLA - at a layer height of 0.2mm and print speed 50mm/s with good results, as it is a fast print you could reduce the layer height further or choose slower print settings to produce a case of even higher quality.