What processes, workflows or software currently exist to manage, schedule, and compensate UX research participants? [on hold]

The question:

What operational systems, methods, softwares, workflows, or personal processes exist for ux researchers to manage, schedule, and compensate their research participants?

Why I ask:

I have 2,000 current users of our app who have opted-in to further research. Keeping them in an excel sheet somewhere is going to become a pain. As a team-of-one researcher, spending the least time possible on participant management, scheduling, and compensation is critical. My hours need to go toward the actual research and analysis!

What I've found so far:

  • This article from Boxes and Arrows describes a use of scheduling software but does not go into too much retail regarding after the research is conducted.

  • Described in the aforementioned article, Calendly offers a convenient way to set your available hours and allow users to choose a time that works for them from within that range. That's all that it does.

  • Validately states "We manage all logistics to recruit from your customer list for your moderated research studies. We’ll oversee all screening, scheduling, and payment." I plan to schedule a product demo to gain further information.

  • While AirTable promotes itself as a tool for UX Research and offers some examples of how to do so, it's still a spreadsheet, a fancy spreadsheet. One still needs to search for, select, schedule, and compensate participants manually.

Further workflows, systems, models, or methods will be listed here as I find them.