The Mobel bell ringing simulator lets you practise change ringing on your Android phone or tablet. You can also display the blue line for any method or composition.
You can practise any method on 4 to 16 bells, ringing a single bell or, for handbell ringers, a pair. You can ring plain courses, or touches with bobs and/or singles that Mobel calls, or spliced. You can conduct touches of single methods, with bobs and/or singles. If you choose the Tower Bells option, Mobel displays pictures of sallies and tail ends, uses tower bell sound, and rings at tower bell speed. If you choose the Hand Bells option, Mobel displays pictures of handbells, uses handbell sound, and rings at handbell speed. You can select from over 22,000 methods, and can edit methods to create new ones, including Doubles Variations. You can ring random compositions that Mobel generates, and you can add specific compositions that you want to practise. You can vary the speed of the ringing, and ring with handstoke gap or cartwheeling. You can have Mobel wait for you if you hesitate while ringing a bell - or it can carry on in perfect rhythm. Optionally, Mobel will give you marks out of 10 for your striking.
Mobel can display the blue line for any method, showing all the rows or just the lines or a grid. Mobel shows the diagram for bobs and singles, if these are defined for the method. Mobel can also show the blue line for compositions that you add. You can use pinch gestures to change the scale of the display, and swipe left and right if the picture is too big for the screen. With the Hand Bells option, Mobel displays the lines for both the bells you'd ring.
The Help pages included with Mobel tell you how to use it - but it's easy!