What is the best way to steer the direction of a sphere in 3D space on an iPad?

Hello,

I have a sphere (like in the picture) and it is moving continuously forward. I want to steer the sphere. My target is iPad and I do not want to use touch INPUT.

MY IDEA :

I think I would have to use either the accelerometer or gyroscope. I am not sure of which would be the best choice. Lets say that I create a default inclination to the device which would be the default orientation/position. I would then want to steer the sphere as per the instruction from the player. It would be mere directional vector and I would apply the required force on the sphere.

OTHER POSSIBILITIES :

Without using touch and for iPad as a target, if you guys have a better creative or different idea to steer the sphere (up/down & leaf/right) kindly let me know. If you guys know any other game of this nature for a tablet, also kindly let me know.

Thank you,

Karsnen.