I have three laptops do I have buy the app on each one?

Nope. Just sign into the app store and download on each one. As long as you are signed into the app store, you can use and receive updates.

You have 3 Macs? Lucky you

Thank you djmagicmoments, yep you can use up to 5 devices with one license (all devices which you are allowed to link to your Apple ID). 

Cheers,Lukas E.

Thank you DJMAGIC…