Load your Sri Lanka TM projected map and you are good to go!
Application that is capable of rendering maps having Sri Lanka coordinate reference system.
Maps should be Transverse Mercator projected and should adhere to SLD99 or Kandawala datum.
To use the tool, load the map in to 'My Maps' folder in the device
Set necessary settings from 'My Map Settings' page!
Use CTDroid application if you want to save locations.
https://play.google.com/store/apps/details?id=msc.research.ctdroidlite&hl=en