Plenty of companies will be selling smartwatches in the future. You can also make your own, but you have to get your hands on the right kit. TinyScreen could be just what you need. It is a tiny, customizable display that lets you play games, get notifications from phone, and view useful information. The device is compatible with iOS 7+ and Android 4.3+.
There is an open source app developed for both iPhone and Android that will allow you to configure the notifications. 3D printed enclosures are also available for the watch. The product is developer friendly. In fact, it has an Arduino library that is optimized for performance and speed. The developers have partnered with Codebender to make it even easier to develop for TinyScreen. You can get expansion boards to do even more. This project is on Kickstarter.