I should add that the developer has been quite responsive to my questions, queries and comments. When I just want to play, any of the three are fine and comparably capable. While I also have Stockfish and Shredder, I spend 95%+ of my computer chess time with Hiarcs. I also use the iPAD OS version similarly. I use Hiarcs on my Mac to play against (~1600), but mostly to play through games in books, to play through games in PGN files, to create my own PGN collections, including adding annotations and variations. The program says it can offer play levels from 750-3200 ELO for the computer version, so enough breadth to accommodate pretty much anyone. The only “tinkering” involves learning how to use the many features. (latest iPadOS versions if Nov 2020, last macOS version is Oct 2020). Hiarcs is alive and well, and does not need tinkering.
HIARCS has been abandoned years ago, AFAIK.
