Rocketdawg is right. I copied the following from a couple of websites. Since following the procedure below I haven't had the problem again.
"It is a problem with the datehookup app, the ads being injected into the RSS feed are redirecting you.
1. Then on your iphone click on settings, general, safari, remove history, remove all cookies and data
2. Then scroll all way down, click on advanced, click on website data, click on remove all website data
3. Then under settings, privacy, advertising turn limit ad tracking to ON (the default is OFF),
and click reset advertising identifier (this is telling the iphone to not allow adtrack* ads and this gives you a new id that is not identifiable by these adtrack ads - so its harder for them to attack your phone.)
4. Now go to safari, go to bookmarks, make sure all history is cleared.
5. Now go to settings, icloud, click safar to OFF if set to ON
That should do it, you are now clear of this idiotic adtrack redirection issue.
*iOS 7 has started using an Advertising Identifier, a “non-permanent device identifier” that allows advertisers to track your device over time through apps that you use. Inside the Privacy > Advertising menu, you’ll find two options. The first, “Limit Ad Tracking,” means that advertisers won’t be able to use the Advertising Identifier to track you on your iPhone, iPad or iPod Touch. If you prefer personalized ads, you might want to leave it on."
Good luck!