Best plugin for searchable image gallery

Hi,

I originally installed Nextgen image gallery but despite being able to tag images it does not seem to have any search functionality. Unless I add WP Gallery Search which I am loathe to spend money on unless I know 100% it works properly and their site their is only an email address to purchase from no ecommerce so not confidence inspiring.

I would like visitors to be able search by image name/tag through my galleries.

Any recommendations – can be paid product or even better if free plugin

Thanks in advance

Simon