It is quite hard to find information about specific combinations of Midi keyboards and particular brands/models of Android phones. This post is in fact nothing more to tell that I am successfully using a CME XKey (25 key on USB) with a Motorola Moto G 2014. There is some latency, but it is just OK for me. I will run a test on a 2013 model as well.
The first XKey I got had a bad middle C key; the current one is better although the Aftertouch is less useful than advertised. It needs serious tweaking in the Windows/Mac/iOS tool CME provides. But Aftertouch is not really an important feature for me; its small form factor in combination with the large keys is really nice.
With Caustic the pitch bend buttons work properly; the sustain button acts a bit weird as you cannot press the same note twice (it will not sound again) when you have the sustain button pressed.
If you have questions about this combination, feel free to ask!