The One Historical Map app is a cool way of looking at Singapore, past and present. Load it up on your browser or download it on Android, and then prepare to be sucked into a time warp. Click on monuments and other buildings to see old pictures, mostly courtesy of the National Heritage Board. There is also a "dual-view" that lets you compare an old map of Singapore alongside the present one. Maps go as far back as 1966. 

The app was launched by the Singapore Land Authority (SLA) on Dec 4 and so far has 200 geo-tagged photos, 100 of them from user uploads. Everyone is encouraged to submit their own to give a more complete picture of Singapore's past.

The app can be found here. iOS users can look out for a comptatible version in the coming weeks.