Что такое App ID и как создать приложение?
AppID is a unique identifier of your social media application. To get an App ID, you need to create an app first.
Creating a Facebook app
To create an app on Facebook, log into your account and go to: https://developers.facebook.com/apps
Once you're there, click "Add a New App".
In the window that will open, select "For Everything Else".
Then name your app, fill in your contact information, and click "Create an App". Next, you will be redirected to the developer panel. Select "Facebook Login" there.
After that choose your platform – Web. Enter your website URL and click "Save". Please note that the website URL should fully match the URL that is specified in the uSocial widget settings.
An AppID can be found in the top menu on the developer panel or under the General Settings tab.