Accountarena vs Notation

Accountarena consists of 3 games, the Debit Go Right, Vocab Battle, and Bilanz Balance. Debit Go Right tests your knowledge on basic Debit and Credit on a given transaction. Vocab Battle needs you to guess an accounting related word, and Bilanz Balance trains your maths skill in calculating the balancing figures. To make it more challenging the games are either set with time limit or number of trials.

Notation is a chess coaching app that teaches you why — not just what. Every chess evaluation comes from Stockfish 18, running entirely on your device. Every pattern, weakness, and tactical motif is detected by hand-tuned on-device classifiers built on decades of coaching theory. The language model's only job is the last step: explaining what the analysis found, in plain English, like a coach sitting next to you. The chess is never generated. It's explained. THREE COACHING FRAMEWORKS Notation is the first chess app to operationalise multiple grandmaster-level coaching frameworks as deterministic measurement: • Dan Heisman's seven positional elements — Mobility, Vulnerability, Centre Control, Coordination, Speed, Time, Flexibility — measured per-position with super-GM baselines • Jeremy Silman's coaching emphasis frames — fifteen frames choosing what to teach at each moment • Jacob Aagaard's positional predicates — Where are the weaknesses? Which is the worst-placed piece? What's the opponent's plan? All computed on-device. All deterministic. The same principles human coaches have used for decades, encoded into classifiers that run before the language model ever sees the position. GAME REVIEW Every game gets a coherent on-device review — no API key needed, no internet, no cost. Template-driven narrative against the full coaching substrate. When you want depth, upgrade once with your own Anthropic or OpenAI API key, o ruse the On Device LLM with no additional costs and the richer review becomes the permanent artefact for that game. Nadia comments on at most six moments — only the ones worth learning from. PDF export of every review. PLAYER PROFILE Style axes — Aggression, Tactical Alertness, Positional Play, Endgame — derived from the substrate with confidence bands. The seven Heisman elements sit below as evidence. Full-screen iPad dashboard. PDF coaching report you could hand to a human coach. OPPONENT SCOUTING & MATCHUP REPORTS Scout reports surface the full eight-axis substrate on any opponent. How-to-play-against framing with concrete suggestions. Player-vs-opponent comparison across all axes with weakest-phase detection. SHADOW — YOUR CHESS TWIN Shadow learns how you play and saves checkpoints. Play yourself from six months ago. See how far you've come. Coming soon: calibrate Shadow to your real-life rivals by importing their games. PLAY ON YOUR PHYSICAL BOARD Pair with Chessnut Air, Pro, Go, Air+ and Move over Bluetooth. Notation tracks every move on real wood while Nadia coaches. PRIVACY BY DESIGN Stockfish on-device. All coaching classifiers on-device. Cohort baselines on-device. Optional cloud AI is bring-your-own-key — your Anthropic or OpenAI API key, your account, your data. We never see it. Leave the field blank and Notation works fully without it. IMPORT YOUR GAMES Connect Lichess or Chess.com. Import PGN files. Nadia analyses everything in the background. £2.99. One-off. No subscription. No ads. No tracking. Yours forever.