Belfry

The sound of church bells ringing changes is unmistakably English, but the craft behind it — bells struck not as tunes but in ever-shifting mathematical orders — looks baffling on paper. Belfry unravels it, turning the daunting "blue line" diagrams that ringers learn from into something you can actually watch happen. Pick a method and the full grid of rows appears, each row a different order of the bells, with your chosen bell's path traced as a continuous line weaving through the changes and the treble optionally picked out beside it. The heart of the app is the step-by-step player. Advance one change at a time and see exactly which pairs of bells swap places between each row, watch the current order arranged on a circle-of-bells diagram, or let it auto-advance at a speed you set while a plain-language note explains what your working bell is doing — hunting up, making places, dodging — at each stage. Because it's a learning tool rather than a recording, the strikes are shown visually with an optional gentle tick, keeping the focus squarely on understanding the patterns. It starts wherever you are. A beginner primer written in plain words explains rounds, changes, place notation and how to read a blue line in the first place, and a bell tracer lets you follow just one bell's path at a time until it clicks. From there you can work through the classics — rounds and call changes, Plain Hunt on several stages, Plain Bob, Grandsire Doubles — each generated by real ringing logic so every row is true and every plain course comes home to rounds exactly as it should. Progressive quizzes then test you: predict the next row, name the bell a line belongs to, judge whether a row is true, or say what a call does. Choose your stage, toggle the treble line, set the trace colour and pace, pick a tower or rope backdrop, and learn at your own speed — completely offline, with no account and no ads. Whether you're a new recruit at your local tower, a curious listener, or a ringer wanting a pocket reference, Belfry makes one of Britain's oldest team crafts finally make visual sense.