Once upon a time Lidl sold a "smartphone camera lens". This was basically an 8x zoom lens with a special case to fit your phone and a mini tripod that falls over when the lens is attached :(
At the time I had an iPhone 4. I then got 5 and had to mod the case to fit. Then I realised the error of my ways and upgraded to a galaxy s6. As a result the whole zoom lens became pointless........UNTIL NOW!!
Lidl, being renowned for quality goods, had put a wee brass ring with the female threads into the case. I simply rescued this ring and super glued it into the hole of the printed adapter.
I have also made the printed adapter such that it slides over my regular case so there's no need for any of this changing cases rubbish. Just slide it on and shoot. Simples.
This particular model is made to fit a Galaxy S6 with a Spigen tough armor case.