Collection: Tablets
Using android for a smart mirror is a popular method, and the most affordable since you get the CPU and the screen in one. Many people are familiar with the OS already and a lot of people have a spare tablet lying around to use for the project.
If you want to use Android but also want to use a bigger display for the project, you can use a Android HDMI TV stick, which plugs directly into a HDMI port, and is powered by a 5V USB micro USB plug.