Time triggered pop-up opt-in form


Has anyone created a time triggered pop-up opt-in form to allow a site visitor full access to either download a pdf or watch a video? 

Would this be a javascript add-on or would this be a 3rd party integration? 


Id try sumome.com super easy to implement and they have great free options.


Can I integrate sumome with unbounce?


The problem w/ this is that if people “signup” via your form on the landing page, they still get the time triggered popup. I’ve been seeking a fix for this. The solution seems to be installing a cookie once people complete your signup form via the Unbounce form, and then setting the Listbuilder (Sumome) popup NOT to trigger w/ the cookie present. However, I have no idea how to do any of those things.