Because the article clearly states that the app is not available yet?
From the article: Five-O is currently in Alpha testing and will roll out to the public on August 18th, 2014, available to both Apple and Android.
That link you posted is to some screenshots.
The closet thing you could link to, in terms of 'how come there is not a single link to the actual app' would be this Google+ 'Community' (don't use G+ unless absolutely necessary so not sure what a G+ community even is) where you can join beta testing: https://plus.google.com/u/0/communities/11815254284529799664...
From the article: Five-O is currently in Alpha testing and will roll out to the public on August 18th, 2014, available to both Apple and Android.
That link you posted is to some screenshots.
The closet thing you could link to, in terms of 'how come there is not a single link to the actual app' would be this Google+ 'Community' (don't use G+ unless absolutely necessary so not sure what a G+ community even is) where you can join beta testing: https://plus.google.com/u/0/communities/11815254284529799664...