Ok, I still do not own an Android phone, but I know many readers of this blog do, and there were several questions how to use the FRDM-KL25Z with Android. And here is something exciting I just saw today: Kai Liu posted information how to connect the FRDM-KL25Z with USB OTG (On-The-Go) to Android: FRDM-KL25Z now talks to Android Phone
He published the S19 file so you can try things out. He still needs to organize the sources and decide on how to publish it (I hope it will be available soon).
If you do not own a FRDM-KL25Z RevE, then you need to consider this post about a hardware change: USB host HID demo times out on FRDM-KL25Z with reproduced USB host