Just a little further clarification as to why these answers are what they are.
1. The USB port only provides power for the 5S. The Apple HDMI adaptor does not provide USB data connectivity, so control of the iPhone is done via bluetooth. Video and audio come from the HDMI, As such, you don't need any proprietary cables to get everything working.
2. Here are the steps to switch the radio from an iPhone to and android or vice versa. 1. Change the cables from the apple HDMI to lightning adaptor to whatever the android needs to connect. This will either be an HDMI to micro or some other cable depending on your phone. You can skip this step by installing a cheap hdmi switcher and having both cables plugged in at once. However, you also need to power both devices at the same time, so you might have to wire in another power source or figure out a way to get both plugged into the USB without cutting the amount of power the devices are receiving. 2. Once you have the cables switched, turn off bluetooth on any of the devices that are in the car, make sure no device is connected, turn off the radio by pressing the "off" button on the second screen of the appradio, go to settings in appradio and switch it from "Digital" to "Others" or vice versa if you're going from Android to 5S, plug the device into the unit, turn bluetooth back on and manually connect, because by now the appradio has stopped trying to auto connect, open your appradio app and congrats you're done. This process will need to be repeated EVERY time you switch devices. Pain In The ASS!
3. The DA-100 does not support USB devices for anything other than software updates. Other AppRadio enabled units that have been made more recently, like the lineup for 2014 support more media sources and do support flash drives.
4. As long as your 5S is connected via bluetooth, you are using the HDMI to lightning adaptor, and the radio is set to Digital, it will work great.
5. The DA-100 does not support bluetooth streaming. The DA-110 and DA200 do. It is rumored that the hardware of the DA-100 is identical to the DA-110 save for the Mirrorlink port that has been added to the DA-110, and that the Parrot Bluetooth chip and subsequent hardware are just a software update away from supporting bluetooth streaming, but Pioneer has not provided such an update, nor have they given any indication that one is coming. For now and for the foreseeable future you can only send audio to the unit with the appropriate cable connected.
I know these answers weren't necessary, but it's always good to make sure everyone fully understands the facts. The DA-100 is still a great radio. I hope you enjoy it.