Nope, sorry, it doesn't and probably will not work on Tiger.
First off, tiger has a different ruby structure that means the underlying script doesn't always work so great on Ruby.
Secondly, and more importantly, it was written for 10.5 with Garbage Collection turned on. it would take a complete code-rewrite to work under Tiger, with memory allocation being done manually, something I'm not altogether good at; I am sorry about this, but I'm afraid whilst Tiger and Leopard look very similar from a user point of view, Apple did a HUGE amount of changes under the hood, making it a lot easier to write apps for 10.5, and I'm afraid you're gonna find a lot of developers will not support Tiger now.
I'll have a look into doing a Tiger version, but I honestly doubt it'll happen.