I was going to follow Jen's advice and buy a special writing timer, but it's that sort of thinking that got me 4 weeks behind on this whole Enchanted 15 thing. Right now I am working on things being Good Enough because if I wait until they are perfect nothing will ever get done. (Also, I'm kind of short on discretionary funds at the moment.)
This phone has been my companion for a very long time. It has gotten dropped on concrete, repeatedly. It has gotten run through the washing machine at least once. It's gotten taken on water rides at theme parks without even a plastic baggie to keep it safe. It's only needed its battery replaced once and that was due to a defect in the battery, apparently, not to the abuse mentioned above. It's a good little phone, and it is in some ways itself an enchanted object (more on those sorts of things next week).
I've got the alarm tone programmed for something other than the tone the phone makes when it rings, and when I'm ready to write it will be ready to be set for 15 minutes and then sing merrily at me when they are over.