I have installed iOS 8 beta 3 on an iPhone 4s. The default camera now supports taking time-lapse videos. Taking a time-lapse video with the camera is very simple because you do not have any options… It takes a frame every second in my experience, at least based on my observations.
Below is the dawn of Tai Wai, Hong Kong, which I took from my bedside counter,
Another one I took while driving,
It’s generally better to take time-lapse videos during busy traffic and daylight. Time-lapse videos of driving on highways at night can result in a dizzying video with little visibility, as shown below (which didn’t turn out so well):