great, been looking for ways to use Alexa outside Echo (which isn't out in the UK). I've got a couple of old android phones lying about which I'd like to use a

great, been looking for ways to use Alexa outside Echo (which isn't out in the UK). I've got a couple of old android phones lying about which I'd like to use as DIY Echos - is there a way to get it working with "OK Alexa" rather than a mouseclick?