Mobile phones can be great media players if it wasn't for the non-optimal sound quality from their regular headphone outputs. Through trial and error we have discovered that some of the USB chips works with Android and Apple devices.
For the added convenience we made the "Android" dac, which is basically the "tiny" model with a MicroUSB plug instead of a USB-A type plug. It connects directly to the microUSB/charger connector on Android phones and works out of the box on some models. Gernerall, software 4.2 needs to be required. The picture shows the Galaxy Mega 6.3 inch screen with the HiFimeDIY Android dac. The sound is much more detailed than the regular headphone out.
We have also tested the Tiny dac connected to a USB HUB (Belikin) and this also works.
Different kernels might give different results. So if you are using a custom kernel, you could try with another kernel.
On iOS devices (iPhone/iPad) it has seemed a bit more complicated. iPads will say that the connected DAC requies too much power when using the Apple Camera Connection Kit. However, when using a non-Apple made USB hub, it does work. The USB hub has a HUB chip which seems to tell the iPad that it is ok that it draws this amount of power. The DAC's doesn't really draw that much power, but the chip will tell the iPad that it might draw up to 250mA. The iPad also shows a message after about a minute saying that "This device is not supported". However it still works perfectly fine.
And, the USB hub doesn't seem to work with iPhone 5. It could possibly be related to the lightning connector. It doesn't work even with the lightning to 30pin adaptor.