So I don't recommend products or apps very often, and when I have, the results have been mixed. (Libro.fm IS a good indie-bookstore-supporting substitute for Audible, but CBD oil as a sleep aid is probably an expensive placebo at best.) But I have NO hesitation in recommending Focusmate, an inexpensive app that gives you a work or study "buddy" on demand.
One of the core problems and paradoxes of productivity work is that many kinds of work demand solitude (for thinking and concentrating), and yet few of us seem to tolerate it well. (We get lonely and restless and distracted.) The most effective solution for many is to work quietly alongside a buddy who is doing the same. A good buddy can be hard to find, however; and even if you're lucky enough to find one, it can still be hard to schedule a time together, and to not chat when you should be working.
Focusmate is really as close to a perfect solution as you can get. It's basically a calendaring program combined with videoconferencing. Use the calendar to sign up for a 50-minute work shift, and the app: (a) matches you with a buddy, and (b) connects you via videoconferencing at the appointed time.
Once online together, you both say hi, spend a few seconds each describing the work you're hoping to accomplish, and get to it. Then, after the shift is over, you each report on how the session went and whether you met your goal(s).
That's it! And for many of us, it works like a charm! Working with a buddy remotely, it turns out, is about the same as working with one sitting next to you. In fact, in some ways it's better: when you find your own buddies, they tend to be people like you. (Fiction writers buddying other fiction writers, for instance.) But on Focusmate I've worked alongside diverse people from four continents who were working on diverse projects, and the diversity itself was fun and motivating.
True, I find some people easier to work with than others: I really want buddies who show up on time (or a bit early), get right to work, and stay seated and focused for the full 50 minutes. (Some people are late and/or always hopping in and out of their chairs, which isn't conducive to my productivity, or--I suspect--their own.) But you can flag those whom you'd rather not buddy with again, and they won't appear on your calendar.
Here's what a couple of friends say about Focusmate (both quoted with permission):
Focusmate is especially worth trying if, due to social distancing or other reasons, you're working from home and find the isolation a challenge. It's cheap--just $5/month, and you can do up to three sessions a week for free--so give it a try!
PS - As always, I receive no commission or other remuneration for this post.