https://www.cnet.com/news/ces-2019-keep-an-eye-on-your-door-with-brinnos-duo-cam/

Images are stored on an SD card. You should get a push alert and an email when the camera senses activity, too, so you can see who's at the door.

Peephole security cameras are becoming increasingly common. Ezviz's Lookout cam, displayed at CES last year, has similar functionality. The idea is that these devices can be used by folks living in apartments with peepholes -- they're supposed to be easy to install, too, avoiding the need for doorbell wiring or any other more permanent solutions.