Camera phone videos, particularly of outside activities, are often rolling and jerky enough to make one practically lose their lunch when viewing them, which is why a camera tripod is a great tool. You can't lug one everywhere however, and it's usually impractical for your iPhone. Apple has added software image stabilization into the iPhone, but there are limits to its effectiveness. You can save yourself and your loved ones some replay discomfort by adding a more robust video stabilizer app to your iPhone library. There are online tools available on sites like YouTube, but for a finer level of control, you might try Emulsio (free), which was just updated on February 24.