It is not just for iDevices as it has cable for use with the WM-Port on Sony walkman and also standard stereo mini. When connected to iDevice, the PHA-1 does not charge the battery. As for battery life, it lasts only 5 hours when connected via digital-in and up to 10 hours when connected via analog-in. It seems to play only up to 16bit/48kHz when connected to iDevice
The article states that the WM-Port of the Sony Walkmans don't output digital so it's really just a LOD cable outputting to the analog input of the amp, which makes the DAC portion of the PHA-1 useless in such a setup.