What are some alternatives?
When comparing CellSend and KDE Connect, you can also consider the following products
Pushbullet - Pushbullet - Your devices working better together
AirDroid - Access Android phone/tablet from computer remotely and securely. Manage SMS, files, photos and videos, WhatsApp, Line, WeChat and more on computer.
Pushover - Real-time notifications on your Android, iPhone, iPad, and Desktop
AirMore - AirMore is a cross-platform toolset that can help you manage any Android device wirelessly.
Join - Join is a marketplace for influencers and advertisers to collaborate.
QPush - QPush is a free service that lets you easily push text and links from PC to iPhone.