We have covered a bunch of interesting tiny cameras in the past. The WiCAM is a wireless coin camera that you can install anywhere to keep an eye on things. It offers Bluetooth and WiFi connectivity. You get a 120-degree wide-angle lens, 500 mAh battery, and temperature sensor.
This 2MP camera has a max video resolution of 640×480, 7fps. It is made with makers in mind. You can install this on a robot, drone, or anything else. More information is available on Kickstarter.