Here’s how you make it work with Mac or Windows7 and upwards, maybe for XP too:
1. Download Blue Stacks and install it.
2. Download Google Play app from Blue Stacks and install it.
3. Launch Google Play and within it, install Fake GPS.
4. Install Tinder in Google Play.
5. Restart Blue Stacks, launch Fake GPS and select wanted coordinates, launch Tinder.
6. Vote for Pirates.
Update 3.4.2014: I have now changed my coordinates to Glasgow (instead of Helsinki), and changing them seemed to take a few hours, if not even a day.
Update 15.4.2014: To actually change your coordinates straight away, you have to log out from Tinder, launch Fake GPS, and then launch Tinder and log in it.
Update 16.4.: Thanks to fdgh’s comment, I now know what the problem was – I forgot the second step, where one needs to install Google Play on Blue Stacks (DUH!). I hope that now people are finally getting this little hack to work with minimum fuss. 🙂