Katie lifts the lid on 'perfect' selfies

Sometimes people use apps to change the way their pics look.

Katie shows us how easy it is to manipulate photos. That's why you should never compare yourself, or the way you look, to the pictures you see online. You are unique and perfect just the way you are, so check out these top tips on how to avoid feeling jealous on social media. 

• Remember that when you share something online, anyone could potentially have access to it. Make sure your profile is private, you think before you post and you know where your photos are going when you share them online.