The Mi Band 2 can show you some notifications, however very limited.
Get this on:
Amazon US: http://amzn.to/1YfPTFR
Amazon UK: http://amzn.to/24GM1Of
Amazon CA: http://amzn.to/1UlSVaa
For text messages you will get this notification:
For Facebook ans its messenger you will see this notification:
Instagram will also show you the above notification. There are probably other apps that may show different notifications on the band however, these are the only apps that i use and tried.
For incoming calls you will see the following notification: