There are many awesome wearable devices available on the market. You could always build your own though. The Pulsar can help. It is a wearable electronic device that allows you to wirelessly its LEDs from your computer or mobile devices. The Pulsar consists of a rechargeable battery, a tiny microcontroller with Bluetooth, and a real-time clock.
The Pulsar can be used for geeky projects and smart home products. The companion app lets you upload patterns easily. This is an open source hardware project. More information is available on Kickstarter.