Snarl - Snarl is a notification system for Windows.
AirDroid - Access Android phone/tablet from computer remotely and securely. Manage SMS, files, photos and videos, WhatsApp, Line, WeChat and more on computer.
Notifu - Notifu, a free open source pop-up balloon utility
Pushbullet - Pushbullet - Your devices working better together
Notify OSD - Canonicals on-screen-display notification agent, implementing the freedesktop.
MyPhoneExplorer - WHAT IS MY PHONE EXPLORER? Imagine if your PC could be used to keep track of your mobile phone? How would you utilize a PC client that connects to your phone? Read more about MyPhoneExplorer.