* The timer's finishing tune is the theme from the fourth movement of Schubert's
  Trout Quintet - the washing-machine tune - played from the score rather than
  recorded. The beeps lost the buzz of a square wave.
* An interval's two colours now mean what they say: the first is the bar before
  the fill has passed it, the second is the bar after. Either can be left empty,
  and the clock shows through.
* Colours can be typed as #RRGGBB as well as picked.
* The timer works to the second: no more hundredths on the bar, and lengths are
  entered as hours, minutes and seconds.
* The timer's lettering no longer grows, shrinks or vanishes while it runs. Its
  size is settled once, before anything is drawn with it.
