The best celebrity FaceApp challenges: From Carrie Underwood to Kevin Hart

The bottle cap challenge is a thing of the past. Say hello to social media's latest viral obsession: FaceApp's old age challenge.

If you've ever wondered what your favorite celebrities will look like in decades from now, we've got the pictures. Everyone from Carrie Underwood to Heidi Klum, Courteney Cox and Sean Lowe are participating in the old age challenge. (Worth noting: The popular mobile app has sparked security concerns over privacy and raised alarms because of its Russian origins.)

If you've been hiding under a rock (or just staying having a summer social media cleanse), The FaceApp challenge morphs what you might look like 20 or more years older via uploading a photo of yourself to the app. Some of our favorite include the Jonas Brothers who captioned the witty photo "When you take a trip to the Year 3000," referencing their hit song Year 3000.

Lance Bass took to his Instagram to share a photo of N*Sync joking, "When we finally reunite." Scroll through all of the best A-list FaceApp challenges in the gallery below! We promise you'll get a laugh out of it.