Flickering is the result of several factors, framerate frequency (the number of frames recorded per second in video, or “FPS”) against a subject that has some frequency in movement or lighting. Fluorescent lights have that noticeable flickering effect on video because of the switching of polarity in electricity known as Alternating Current, some countries have it in 50 hertz (50 times per second); and some in 60 hertz. Changing your camera’s recording frequency may help, or completely avoid video-recording fluorescent lights or TV screens.

Tottering is common when the camera is not properly mounted. We suggest that you tighten all mounts, making sure that the surface where the mount is attached is properly anchored to something that doesn't vibrate or shake. 
In some SJCAM models where a Gyro is available, turn the feature on to make the image look more stable. 

We have an array of mounts for different purposes, check out our online store here: www.sjcamhd.com/shop to see a full list of mounts.