Pokemon GO is free to download, but you'll probably have noticed the in-game shop where you can spend real money on virtual items.
You can get Pokeballs, incense, lure modules, lucky eggs, and items that boost the number of items you can carry, eggs you can incubate, and Pokemon you can store.
But if you want to play the game without spending a penny,
Visit loads of PokeStops
The truly important items in the shop - like Pokeballs, incense, potions, and razz berries - can all be found by visiting PokeStops. Just walk up to it, tap on the icon on the map, and spin the dial.
Remember that PokeStops refresh (going from purple to blue) every few minutes so if there are a bunch in your local area just keep doing a loop until you have a huge stock of items.
Hold onto gyms
You'll get gold, which can be spent in the shop, by holding onto a gym. If you defeat a gym leader and station your own critter on the gym, you'll earn 10 Pokecoins a day.
And you can do that with multiple gyms, with a limit of 100 coins a day.
To claim this bonus cash, go into the shop screen and tap on the shield.
Look out for lures
The nice thing about lures - the pricey module that can be attached to a PokeStop and entice loads of monsters - is that everyone gets the benefit.
So if you see a lure on your map (it looks like a PokeStop surrounded by pink petals) make a beeline to that point and the reap the benefits of someone else's generosity.
Every time you level you you'll get a bunch of freebies such as potions, Pokeballs, and razz berries. You can level up by catching critters, hatching eggs, and beating gyms.