There's a few well-known tools to estimate cost of living in a given location. However, none of them could answer an obvious question I have always had:
How much money would my family need to retain same life style after moving to a different location?
It didn't feel right, and I decided to build my own tool tailored to actual user needs—not answering how much more expensive a kilogram of tomatoes is in New York compared to Prague.
DISCLAIMER: I have not been maintaining the app since it's launch, so the data points it's based on are quite stale, as well as it works only in a desktop browser.