Travel / Best place to exchange money in Poland? [98]

A couple of years ago I changed GBP 200 with the first kantor I came across in Warsaw. I thought there couldn't be much difference in the rates between different kantors. Turns out there is. As I was walking away, I did a quick mental calculation and realised I had been given a terrible rate of exchange. I went to another kantor and he told me to return to the original kantor and demand my money back. I did just that and the guy gave me the 'bank rate' - he literally gave me an extra PLN 130! I know I was an idiot for not checking the rates in the first place. The rates board was on a side wall out of the way. Following this I thought I would make an app showing the kantors in Warsaw with links to their phone numbers and websites (if any) and directions. Many months later I released the app on the App Store (I'm working on an Android version). Here's a link to the landing page fx-warsaw.com. It's free.