WD Photos app on iphone

Ok, not sure what I’m doing wrong.  I just installed the WD Photos app on my iphone, logged into my My Book Live 2TB drive, remote access tab, and generated an access code.  It now says *waiting. Launch the app on the iphone and the WD Photos splash screen comes up for 3 seconds then closes.  Nothing happens!  I deleted and re-installed the app and still does not work.

What am I missing?

What IOS version do you have in your iPhone?

Thanks.  I upgraded the IOS to ver 5 and now it works!