The Ourkens Retractable Universal Charging cable may be on of the most convenient cables I have ever come across. It is roughly 6in long while coiled and 3.3 feet when fully retracted. It features Apple 30 pin, micro-USB, micro-USB 3.0, and Lightning connectors at one end and a USB 2.0 type-A connector at the other. The only connector missing is USB Type-C and this would be the ultimate charging cable. I do wish they had made the head end USB 3.0 so that the micro-USB 3.0 connector could be fully utilized when transferring data. The cable is well made and has a tangle free flat design as well as decent strain reliefs. I had no problem using this cable to charge every device I tried.
If you are interested in purchasing this cable it can be found here.