Suggestion for enhancement:
upon completion of a number, immediately mark the number button yellow (or some other colour). Currently the yellow line only appears when you press the number button again or switch to another number. This means that sometimes I'm checking all boxes to see whether they contain the number I'm working on, whereas it would be great if this could be shown visually immediately when entering the last of that particular number.
Suggestion for enhancement: upon completion of a number, immediately mark the number button yellow (or some other colour). Currently the yellow line only appears when you press the number button again or switch to another number. This means that sometimes I'm checking all boxes to see whether they contain the number I'm working on, whereas it would be great if this could be shown visually immediately when entering the last of that particular number.