Online testing

https://www.browserling.com/ – Run real desktop browsers in virtual machines. Don’t use emulators or fake browsers. Not just screenshots! You can interact with the browsers live as if they were installed on your computer.

https://appetize.io/ – Run native mobile apps in your browser. For app previews, training, customer support, development, testing, and more… is an online iOS Simulator and Android Emulator that will help you run iPhone, iPad, Mobile Safari, APK, mobile apps in your browser!

https://www.onworks.net/ – Free online VPS hosting provider that gives cloud services like free workstations, online AntiVirus, free VPN secure proxies, and free personal and business email. Free VPS can be based on CentOS, Fedora, Ubuntu and Debian. Some of them are customized to be like Windows online or MacOS online.