You may, at some stage, have given an app access to your Social Media accounts. Finding out how to extract yourself from their system is not as easy... so here's a list of the main networks and how to remove unwanted access.
How to Revoke Access to your Twitter account
When you sign up for some services you do so by giving them access to your Twitter account.
To see who has access to your Twitter Account go to https://twitter.com/settings/applications
You can see who you have given access to and you can hit the Revoke Access button to remove them.
How to Revoke Access to your LinkedIn account
You can also give access to several apps via your LinkedIn Account.
To see who has access to your LinkedIn Account go to https://www.linkedin.com/psettings/third-party-applications
The descriptions are a little more vague in LinkedIn so if you're unsure then remove them.
How to Revoke Access to your Facebook account
Wow, I just remove 14 out of 17 apps that I had, over the years, given access to my Facebook data.
To see who has access to your Facebook Account go to https://www.facebook.com/settings?tab=applications
Phew, I fell like I've just done a spring clean.