There’s a long history of building things in Altoid tins, but the Pi-Tac 1.0 uses a Pi Zero W inside a Tic-Tac box. In addition to the processors, there is a tiny OLED display and a battery controller. According to a Reddit post, [Deathonater] plans to use it as a WiFi access point.
The display and the battery/power controller are from AdaFruit. You can find some sample code for the battery controller if you want to duplicate the design. You can also opt for an enhanced version that can report the battery state readily.
[Deathonater] has plans to enhance the setup to include a manual soft shutdown button and a USB port to support an Ethernet adapter. A network connection is something of a key requirement if it is going to be an access point. As someone pointed out on the Reddit post, you can buy an access point without any trouble, but — then again — when has that ever stopped any of us from building something?
We wish he’d have more explicit build notes, but given the links to the libraries and the hardware, really the only hard thing to figure out is the layout in the container and you can get that from the pictures.