Want to create image effect – what plugin ?

Hi,

Want to create effect for image (image gallery) as here:
http://www.uzuolaidusiuvimasmodeliavimas.com/blogas/

Image has description below.
When I hover above image, text appears.

This site is created using customizr theme.
I am not sure if this effect is given by theme or by some plugin ?

Any ideas are welcome.

Regards,
Edas