hello irene .
for images seo , you can do it by yourself without any plugin .
while uploading images , you need to be smart and make the picture speeks itself : for example you have an image of a white dog hunting , you should rename the picture to be like ” white dog doing … or describe picture backgrounds, etc “
afetr doing that , you avoid uploading poor images like the ones named ” download.jpg, images.jpg .. ” and next step is , set the alt tag . you can copy the title of the image , which is the name you gave the image before , and place it in the tag . next step , give the image a quick description . like a small paragraph . after doing that , wait till your content gets crawled by google bot, and then test by going to google images and try some keywords already set in the image title and description .
note: i use wordpress 3.9.1 and it still supports what i told above .
thats how you can get some traffic from image search engines . luck to you , irene .