CellSend - CellSend is a free service for sharing texts, links and pictures across all your devices.
Pushover - Real-time notifications on your Android, iPhone, iPad, and Desktop
Pushbullet - Pushbullet - Your devices working better together
Tresorit Send - Ultra-secure, end-to-end encrypted large file sharing.
Gotify - a simple self-hosted server for sending and receiving messages
Mobizen - Use your Android from a web browser or desktop.