Image slider with thumbnail gallery plug in??

Hi everyone,

I’ve been trying to find an image slider with thumbnail navigation for free but with no success. I tried Wow Slider but there’s an unattractive watermark in the free version, understandable, but not something I want on a photography site. Meta Slider has a nice one but since this is non-profit work, paying $20 is my last resort.

Any suggestions would be greatly appreciated, thanks!