Weylus is described as 'Use your tablet as graphic tablet/touch screen on your computer' and is an app in the Remote Work & Education category. There are more than 10 alternatives to Weylus for a variety of platforms, including Mac, Windows, iPad, Android and iPhone. The best alternative is spacedesk, which is free. Other great apps like Weylus are Deskreen (Free, Open Source), Duet Display (Paid), iDisplay (Paid) and TwomonUSB (Paid).
The multi-monitor display extension app, spacedesk lets you use other devices and computers on your LAN (Local Area Network) as monitors for your Windows desktop. At least 2 machines are needed to operate spacedesk.
Turn your iPad/iPhone or Android tablet or smartphone into a convenient side monitor for your Windows or Mac desktop. iDisplay is a universal app specially optimized for iPad, iPhone, iPod Touch, and Android devices screens.