Yeah, I've been working on Upwork for about 1.5 years now and it has been such a vast improvement over other freelancing sites - both in terms of the size and scope of the projects and in terms of the types of clients available. Not one of my hourly clients has ever insisted that I use the monitoring app; yet I do it anyway because then I don't underbill and the payments are guaranteed.

In my mind, the screenshot every 10 minutes is no more invasive than sitting next to a colleague in an office and if you want to do something private, simply pause the timer and do it on your own time. Upwork is a pretty great site if you're a freelancer.