So, some phone and tablet game apps allow you to use a separate bluetooth controller. This helps alleviate the two main problems with "on screen" joysticks: covering up a big chunk of your screen with your fingers, and the loss of fine control as your fingers start getting more draggy across the glass over time
Here's an example of one of these bluetooth controllers (Steel Series Free):
Will the Spark support this while using phone control (still limited to wifi range naturally)?
Here's an example of one of these bluetooth controllers (Steel Series Free):

Will the Spark support this while using phone control (still limited to wifi range naturally)?