On the MAS ViewPic has received 9 ratings and has a 3 star rating overall.
This is a bit concerning:
On the dev's website http://goo.gl/PcjYTf
an icon at the bottom says this app was "reviewed by mac.informer." When I click the link and go to the site http://goo.gl/H0aw1o
then use the search box to look for ViewPic, the app's page says "Editor rating - none" and "User rating - none."
So it doesn't look like the app was ever reviewed by ANYONE on that site.
Here on MU Lyn has 4 stars and costs 5 times as much. http://goo.gl/PgClv
But Xee also has 4 stars and looks like a bargain at only $3.99. http://goo.gl/n2FVo
I haven't tried either but think I'll try both concurrently, and I might give ViewPic a whirl too.