Gyro-based mechanical stabilization in robotics
There are MEMS gyroscopes which have everything packaged into a single chip and provide a digital bus for communication. For most applications these are a suitable substitute to a full-sized mechanical gyroscope, and are really easy to use.

However, because your post says you want a plane the be parallel to the ground, a gyroscope may not be an appropriate tool by itself because it measures orientation relative to a set internal reference point; this will only work if you expect your ground to be flat (or piecewise flat like stairs). It won't work if you want to keep your plane to follow the contour of a hill it is flying over. You will need some other feedback mechanism (likely complex optical sensing such as LIDAR) if you want your plane to follow the contours of the ground.