Ticking clocks are used so often in movies for a simple reason: they work. Just as deadlines unleash tension, fear, and adrenaline in our everyday lives, a danger with a fixed time of arrival motivates action in movies. Ranker offers a list of 25 classic movies with ticking clocks including “Back to the Future,” “Terminator 2: Judgement Day,” “Apollo 13,” and  “The Martian.” While often ticking clocks are metaphorical, there are many examples of a literal, physical clock ticking down. There’s the A-bomb in the last act of “Goldfinger” and—more recently—in Peter Chan’s iPhone X short film “Three Minutes.”

In this seven-minute Chinese drama, sponsored by Apple, a mother who works as a train conductor has a brief reunion with her son on a station platform. A superimposed clock counts down the precious seconds, adding to the pathos of meeting.

Chan’s movie, which in less than a month, got more than 2 million views on YouTube, employs many other techniques such as overhead angles, time bending, two shots (two characters interacting with each other), and practical lighting (a sparkler illuminating the night). The film can be used as a cinematography text, while it demonstrates that high production values you can get with a smartphone. The director created three helpful behind-the-scenes videos: Time-lapse with iPhone X, Unique Perspectives (camera angles), and Portrait Lighting with iPhone X.

Ticking clocks can work in other genres. For example, if you’re making a commercial about a store’s speed of service, showing a clock–or just adding ticking to the sound track—could make a difference. The same device might be effective in a blog in which you promise to explain how to fix a leaky faucet in 60 seconds.

If you know of other movies that successfully employ ticking clocks, we invite you to list them in the comments section. And if you’ve made such a movie, you can tell us about it at info@mobilemoviemaking.com

You can learn more about Peter Chan at IMDb and in a New York Times Q & A about “Making Movies in China.”

“Three Minutes” was chosen as a “Mobile Movie of the Week” by the editors of MobileMovieMaking.com.