What? Just to view pictures?
Not as hard as you might think on a Mac - and you don't need an app for that.
The OS X system does that natively as part of the Quick-View feature:
Open your folder of pictures, and select all files (Command-A)
Press your space bar.
Use your arrow keys to go through your pictures.
Click the full-screen menu icon to lose the background distractions, if you like.
You can click Play to let the pictures advance automatically, as a slide show.
I use this feature all the time on a Mac.