It's a good idea to perform a security audit of your online accounts from time-to-time:
(Google, Twitter, Facebook, Instagram, etc.)
- Note: Email is most important since this is the key to all of your other accounts.
When in doubt, change your password. Have a feeling that someone might be reading your mail, but not sure which app is to blame? Changing your password instantly invalidates all your Google and Facebook OAuth tokens, though Twitter tokens persist after password changes.
- App permissions: https://accounts.google.com/b/0/IssuedAuthSubTokens
- Device Activity: https://myaccount.google.com/device-activity
- Last Account Activity: https://support.google.com/mail/answer/45938?hl=en&ctx=gmail
- Security Checkup: https://myaccount.google.com/security-checkup
- Apps Tab - Account Settings: https://twitter.com/settings/applications
- Facebook Application Settings: https://www.facebook.com/settings/?tab=applications