I have seen a few of these on various websites and think they look so cool.
Does anyone know to do this? or know of any tutorials about how to do it?
I cant decide what the best software would be to create it.
Aside of the fact that this is an awfully sloppy hack job (the liquid flows behind the sieve, not through it, and there are artifacts from poor masking), such stuff is easy enough to create even in PS. It's basically just two sequences stacked on top of each other whereby one "sequence" is simply a still image stretched out for the whole duration. Using a dedicated video/ film compositing program like After Effects would make things easier, of course.