What apps can I test?
With unmoderated online usability testing you can test web apps and desktop apps. Testers will be asked to install a screen recorder that will record anything they do on their screen.
If you have a mobile app you'd like to test, you can either give a URL to a prototype that can be simulated in the web browser or, even better, invite testers to personal meetings. Videos will not help you to see the actual experience that a tester has with your app, and neither will a phone call.