Good beans, a decent grinder, and the cup still misses. Too many variables, and they hide behind each other.
The app does not lecture you. You rate the brew, and you get a specific move back: grind finer, more dose, less water.
What you brewed — method, grinder clicks, dose and water. The ratio works itself out.
How it landed — two axes: taste runs sour to bitter, body runs light to heavy.
What to change — one sentence, the new numbers, and the delta. Here: −2 clicks, +1 g.
The whole app sits on this picture. Sour and bitter are two ends of one axis; light and heavy body are the other. The further your rating sits from the middle, the bigger the correction.
Turkish roasters, with full specs and where to buy them. The ones I have tried carry my own tasting note and score.
You do not need the app for these — the most common questions are answered right here.