Over the break I made Service Wait , a simple smart phone timer application with a start and stop button that sets values you can tweak later to get the elapsed time. It’s useful to see how much time you have wasted waiting for something, or for working out times for time sheets. I made it for my mum for Christmas.
In other projects I have used knockout.js to create view models. This time I just worked with jQuery and jQuery mobile directly and for a simple problem I would recommend starting out by working this way. I prefer to add a framework or tool when it solves an issue.
I built the site using jQuery mobile which has great support for most smart phones. However I was primarily concerned with optimising for use on iPhones/iOS. I found that on iOS you could show a time keyboard by specifying the type as a time like so.
One idea I had that may come in the future is a tweet button, which basically allows you to whinge on twitter about how long you had to wait with a great deal of precision.