I have developed a simple location aware iPhone application which is functionally working very well to our expectations except in the low memory condition of the phone .
It's up to you to decide what to do in didReceiveMemoryWarning. The OS is telling you that memory is low, and you need to free up as much as you can as soon as you can. The idea is that you should free any cached data, unload views that aren't visible, etc. The details are application specific.