Looking for a video ad content locker

Hey all,

Im looking for a content locker that displays an ad before the user gets access or a pop up modal that cant be closed until the add is finished.

adscendmedia seems to have one for mobile but i need desktop as well.
yashi also has one that i read of, but i cant find any info about it on the website.

Anyone had any experience with such a platform? I would love to know how you went.

Thanks.