Your GoodBarber iOS and HTML5 apps have native sharing features for Facebook, Twitter, Linkedin, Tumblr and Pocket. Your Android app has native sharing features for Facebook, Twitter and Pocket.
Before building your app you will be asked to follow the procedure to declare your app on these networks. This process is optional: you can ask to disable all the sharing features from your app. But, trust me, that wouldn't be a good idea!
For each social network that you'll set up, you'll have to enter the credentials that you'll find in their developer area. If you don't enter your Facebook app id, for instance, the Facebook features will be disabled in your app.
Keep in mind that, unfortunately, changing these settings implies to build your app and submit it again to the store. So you should think about it before the first publication.
In the specific case of Facebook, you'll have to follow a specific procedure to enable the "like" action. As it is an OpenGraph action, you need to submit it for approval to Facebook. Until Facebook has approved your like action, users won't be able to use it in your app.