This uses a swipe tool to explore the changes in the growth of key cities.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjs5WktEse_G1qWRGyKvr5F1NUztG-UC5vLJmbjTBXoWcfM-NbtfkiU3LUT04UxytIaVwu5kRhVq934V7-VsD5CtpDS9Y19bAIGSMvRYEc7-5HvikUoTqSRRKXGYUej8mL5bfKDL6D_yBU/s640/Urban_growth_explorer.png)
It's also worth remembering that there are some similar tools in Digimap for Schools - here's a short video explaining how that can work too...
A project originally funded by the Royal Geographical Society (with IBG) with an Innovative Geography Teaching Grant to develop teaching ideas for using Google Earth in the Geography classroom, expanded to include ArcGIS Online in 2014