You can link your Twitter, Facebook, and LinkedIn accounts directly from the PostBeyond mobile apps for iOS and Android.
First, go to your Profile section
From your profile, go to your settings.
In your settings, select 'Linked Accounts'
From there, switch on the toggles for any Social Account you would like to connect
Authenticate your accounts with the social networks
Once you have authenticated an account, the toggle will be blue and you can now share to that network