If the code for the ATTiny is published, then you could probably adapt the code to use pretty much any Arduino style microcontroller.
Even if it isn't I suspect writing suitable code to drive a couple of GPIO lines in such a way as to send a motor scurrying backwards and forwards is not going to take a lot of effort. A while back I needed to agitate some chemical or other for an hour or so. I used a microcontroller (an STM32diono blue pill board for what its worth) to control a small RC servo, which I used to pull a piece of string back and forth, which rocked a plastic milk bottle. It did the trick. Arguably I could have better spent my time sitting with a cup of coffee and rocking the bottle back and forward by hand, but where's the fun in that?
They look pretty useful. ebay also has quite a number of choices, including these rather strange looking ones.