Productivity app has stolen my Safari and has now dissaperared. I phone 5s

That was the unusual thing, the "productivity" folder was not visible on any page therefor I could not enter it to retrieve my App. Also , the folder "productivity" was not in the list on the "settings" Tab. Where did it come from?? The Spotlight search did find and open Safari but did not help locate the App. I eventually got it back by taking the iTunes Store App and placing it in a folder called "lifestyle" Which came up when I tried to superimpose itunes store on top of another App. Once I put it in the "lifestyle App I took it back out and "Safari" has magically re appeared in its slot on the page. Still confused and I resolved this more by luck than good judgement. Thank you for your helpful suggestions kb1951.