Algodoo

Press enter or return to turn it on, press enter or return to also
turn it off. V1.0.4 update: press \ to toggle rain.
(PLS READ: How to use Unclogger (now unclogs small bits!): Step 1. put the
unclogger at the hole, Step 2. If your unclogging small bits, then just drag
the unclogger to make it go into the pipe and repeat till you ain't see any.)