I have blogged about using time-lapse before and it appears in our iPad Teacher Guide App (www.ipadteachers.com), notably to capture shadows moving across a playground. We use the time-lapse feature in I Can Animate a lot and even more recently where I have supported a number of schools who are capturing mini-beasts and even chicks hatching. The good thing about it is that it can be used with all year groups across a range of subjects but predominantly in Science.
The image above shows a typical workflow that we use combining I Can Animate, iMovie and Book Creator with Showbie used as the resource and assessment tool. The rule that we follow is that if the process takes less than a day (e.g Shadows across the playground, dough rising etc) then we use time-lapse. If it is longer than a day (e.g seeds growing) then we take the photos in I Can Animate manually because we want to use the iPads inbetween time.