We’ve all seen YouTube videos like the above, showing a time-lapse of a person’s changing face over time. If you’re anything like me, you’ve momentarily thought about how interesting it would be to create a similar video for yourself, just to see how much your features alter from month-to-month, or year-to-year — only to drop the idea because you realize you’ll never remember to take selfies every single day.

Well, Grzegorz Aksamit’s suitably-titled Selfie App can help you, since it will automatically trigger your MacBook’s built-in iSight camera every time you lift the notebook’s lid, or wake your iMac up from its slumber. Useful, huh?

To be fair, the app’s not only good for narcissistic reasons, as there are clear security applications to being able to see who it is that uses your Mac — particularly if you live in a shared house and keep sensitive material on your notebook. If you’ve had a flatmate continually deny using your Mac when you’re away, despite clear evidence to the contrary, this is a clever way of catching them in the act.

At $4.99 from the Mac App Store, the price is a bit steep for something that is most likely trivial, but if you’ve got the right use in mind for it, Selfie App could definitely be worth it.

Put it this way: it’s certainly cheaper than buying a dedicated selfie drone or iPhone selfie brush (and, yes, both of those do exist!)