It's the standard in match registration and scoring. I've downloaded the app which is the app for the match end, not the competitor end (to register or check your matches you use the WWW portal) so I haven't tried to do anything with it. I did a contribution to "help" the app owner and so I could have an emoji next to my name. I've always been curious how their business model worked. I made all sorts of assumptions about how they probably charged Match Directors for certain features which is why some don't use the pay-online feature.
SO I WAS ALL WRONG. I might still be wrong, but here goes. Steer me to sources to fill in the gaps or correct me if I'm wrong.
PS created, by an individual (name?) who did it as his contribution to the shooting sports. It is free to use both from the Match side and the Competitor side. PS does charge for ads. Scoring Tech will create most any format (discipline) for use in scoring for no charge. Which begs the question of why CMP/NRA and GSSF don't use it. Or use it more. Maybe they feel lack of control over format and data.
Here's the neat part now that I've started playing with it. You can setup your own Match for practice. Record your times and scores to analyze later. Works great for Steel Challenge since your just recording times of strings with no misses. I haven't dug into it but it looks like they've added AI target scoring and shot timer to the app!!! < I was wrong> Using the AMG-labs Commander timer you can bring over the times of not just live fire but dry fire as well, at least time to first shot/click. This is where revolvers have an edge so we can actually record whole strings of dry fire with split times.
So fill me in here, I'm really just getting to know PS from the match side beyond entering scores at matches.