You found a bug! We've classified it as
We encourage you to continue the discussion and to find an acceptable workaround while we work on a permanent fix.
Checkbox field with long label goes offscreen
When you have a checkbox with a long label, the checkbox itself becomes invisible (goes offscreen) and you need to scroll horizontally to see it.
This is easily reproduced in your documentation example for Checkbox (http://docs.sencha.com/touch/2-0/#!/...eld.Checkbox): change the label for the first checkbox from 'Tomato' to 'Tomatoooooooooooooooooooooooooooooooo' to see it.
Thank you for the report.
Sencha - Sencha Touch Dev Team
This seems like a weird issue with Webkit. If you set the label width to a px value, it works as expected.
I will continue to investigate.