Do you know which website i am looking for?

About one or two years ago i found this website where you could search in Youtube clips and then they were shown to you in a screen with multiple little screens (you could put in how many screens you wanted yourself).
So, there were, let’s say, 12 little the same Youtube clips showing and they all started with a little time difference.
I tried to find it myself many times but unsuccesfully so.
Does anyone of you know what i am talking about, and even better, know where i can find it?