Did the ultimate test for cooktimer yesterday, three things cooking with different times. Works great.

How long were you leaving it before moving into testing

One small thing I would like to discuss, if you select an item then change the time. The item still shows the previous item, over Choose item.

Is this by design or just the default behaviour for that list widget?

Examples:-
If you where cooking "pasta" for 25 minutes and you had that in the item list; the name says "pasta".
Time elapses and you reuse that timer for the apple pie in for 40 minutes. You have never done an "apple pie" before so don't have it in the edit items, (the other timers are in use so I new one cannot be started) the timer still says "pasta".
With out adding the item "apple pie", or changing to another item; there is no way to remove the "pasta" name.

OTOH you could want to extent the pasta's time due to it not being done so resetting the name is not ideal.