There aren't any "free money" cheats in Pokémon Go. There is a way to get PokéCoins without paying real money — but you're still going to have to work for it.
How to get free coins in Pokémon Go: Hit the gym every day
The only way to get "free" PokéCoins is to install your Pokémon at gyms to help defend them. You can earn 10 PokéCoins per gym defender you have stationed at a gym. Then you have to wait 21 hours before you can cash in the bonus again.
To get the most PokéCoins this way, figure out a selection of gyms that you can walk to and conquer easily. If your team already controls the gym, you can place one of your Pokémon there to help defend if there's a slot available. Then cash in the shop bonus once you have as many defenders stationed at gyms as possible by tapping on the shield icon in the upper-right corner of the shop.
This may only amount to 20 or 30 PokéCoins per day on a good day, but if you're not a fan of microtransactions, then defending gyms is the only other way to earn PokéCoins.
Then again, if you'd rather just shell out real money for PokéCoins, that's always an option. You can get a lot of coins for not that much cash, starting at 100 coins for just 99 cents.
More Pokémon Go guides, tips, tricks and updates
Check out Mic's Pokémon Go tips and tricks. Here are guides on how to get stardust, how to determine how long it will take you to reach level 40, the kind of Pokémon you get from 10 km eggs, how to create new PokéStops, how to maximize your chances of catching Pokémon and how PokéStops distribute Pokémon eggs. Also check out how to catch Gen 2 baby Pokémon, our analysis of post-balance update Chansey and Rhydon and everything you need to know about finding the long-awaited Pokémon Ditto.