Looking for Plugin to prevent account sharing

Hello,

I am selling a web application that is implemented into my website. Users first need to pay to get access to it. So far so good.

However, I would like to prevent users from excessive account sharing. I could not really find any plugin related to this, nor can I think of a very good way to prevent this.
I am aware that there is no 100% secure way to avoid this, also because a user could be logged in from his phone and his Laptop and PC which is acceptable.
I am looking for something that at least would flag an account, or send me a warning email if for example a user account is suddenly logged in 10 times from 10 different IP addresses at the same time. This way I can take manual action.

I am open to any suggestion on plugins that perform similar tasks.