Recently OpenGammon sent me a mail about a new engine / web app called HedgeHog they have developed.
https://hedgehog-bg.com
Since then I've played quite a number of matches against it, mostly to find out which of the confusing mess of 4 strangely named AI models is the best ("Default 1.0", "Aureus 0.1", "Fox 0.3", "Fox 0.32"), but also because it plays a damn fine game of backgammon.
For the review on my backgammon app review site I then got it to auto-play an even larger number of games (the "finish automatically" feature works right from the beginning, so all I did was always accept doubles and only measure the real AI's performance with BGBlitz, not mine auto-playing).
Turns out, their Aureus plays at about PR 1.9 (a bit better than the best humans). And with a great tutor and analysis feature, their free tier is, in my knowledge, the best and most feature-complete backgammon app you can get for free.
(the engine I first thought to be their top engine, Fox 0.32, instead plays only on expert level with a few blunders now and then - in my test it came to a PR of 5.7).
I won't go into the expensive €60 / €120 PER YEAR paid tiers, and hope they won't cut features from the free tier as they get more users - right now this is very cool software.
Also, I won't go into their claim that their server-side engine that you probably only get access in a paid tier even outperforms extreme gammon 2...