I just had one these arrive today.
It Measure gauss of magnets and motors - very simple device.
Also has a RPM checker, which is quite handy. All have you have to do is use a white sticker on a tyre or on the crown gear, just remove body if you really want to.
No torque checking that I am aware of.
will post a review after playing with it a bit more.
DS Pocket Checker