Thanks for submitting this! It's a very old little project of mine that hasn't really been updated in 6-7 years. It's built with Google Maps, but since then, I have created Leaflet (http://leafletjs.com/), now the most popular mapping library, and also currently work on modern vector map rendering tech (https://mapbox.com/maps/) as a part of Mapbox. So I guess a V2 of this page is long overdue. :)
@vladimir_agafonkin your site is very popular among Singaporeans planning to buy government apartments. I've seen your site pop up several times while researching on which is the best apartment unit to purchase.
SunCalc
Makerpad