Pushbullet - Pushbullet - Your devices working better together
Pushover - Real-time notifications on your Android, iPhone, iPad, and Desktop
AirDroid - Access Android phone/tablet from computer remotely and securely. Manage SMS, files, photos and videos, WhatsApp, Line, WeChat and more on computer.
AirMore - AirMore is a cross-platform toolset that can help you manage any Android device wirelessly.
Gotify - a simple self-hosted server for sending and receiving messages
Pushjet - Free open source push notifications