I remember a guy here said that Apple wants G2 connections
Here is my example following Michael's guidelines

A-draw a rectangle and fillet corners G2
B-two arcs then sweep where red is section and blue is rail
C-extrude filleted rectangle to cut sweeped surface
D-select edges of cutted surface and extrude more than you need,than union both surfaces
E-select edges and fillet G2
F-draw a line to cut excess of extrusion,according with height of the phone



Pay attention about fillet radius values:G2 needs good conditions to work succesfully while Circular or G1 works without problems
This is final result where all is G2...i'm not able to do better :)
Check the file attached




M