They are online Android/iOS emulators in browser.
They are Manymo http://manymo.com and https://appetize.io .<p>Do you know how to implement a website like that? And what computer hardware should be using?<p>Should we run an actual Android/iOS phone behind?<p>Welcome to talk!
I don't know about those emulators (probably they run the emulator on a powerful server and just send the display to the web browser); but emulators are just virtual machines, that is, mere programs, and web browsers can be programmed in JavaScript. So there, you have a X86 emulator written in JavaScript, running on your browser, and booting linux, and any linux programs you care to run on it:<p><a href="http://bellard.org/jslinux/" rel="nofollow">http://bellard.org/jslinux/</a>