The description says, “For serious chess players,” and another review states “If you get one chess app, make it this one.” Both are true. Other chess apps have lots of eye candy. However, when it comes to what it takes to manage your repertoire, analyze your games, and other important functions you would expect from a chess app for anyone who is half-way serious about their games, then _nothing_ on the App Store comes even close to Chess Studio: Manage your PGN databases, analyze, create opening tables, download from TWIC and PGN Mentor, … Yes, it has its interface idiosyncrasies and its own way of doing things but one will easily get used to it and understand the rationale behind its presentation. I especially like how the analysis (now using Stockfish 16) shows immediate graphic feedback with labeled arrows with different transparent colors akin to Nibbler/Lc0.This is a fantastic app for importing games played on either iPad or iPhone and analyzing them. Easily move PGN databases between iCloud, DropBox and local storage. Create opening books from your games on mobile? Unheard of, but this app does it! The more I use it, the better it feels. I cannot thank the author enough for such a useful and functional chess app!