This app was mentioned in 7 comments, with an average of 2.00 upvotes
I found a similar selfie time lapse app for android users here. I like this idea, I think I'll give it a go. Thanks for the suggestion!
I use Photochron on Android to do the same thing (Although I'm not even 1 year in yet!). It gives you a notification to take a selfie at whatever time you set. Gives a little overlay on the screen so you can position your face correctly. Photos get automatically backed-up to Google Drive. Takes like 10 seconds a day
The only camera app I'm aware of that does something like this is PhotoChron. It's basically for taking a selfie every day and has an overlay of the previous photo so you can line your face up for time-lapses.
Anyway, can't say I recommend the app, but it does something like what you're looking for so you might look at it and/or similar apps. Good luck!
I've been using PhotoChron for a selfie a day timelapse but I guess you can try it out with the rear camera. It has the transparency for the previous picture too
Made me curious so I got looking around...Photochron may do what you want. Called timelapse selfie but can use back camera too. Good Luck