program to monitor time spent on an Ap monthly

Looking at my 10 pages of aps I have on my Iphone 5s 16GB (latest 9.0.2 ) and remaining size of memory is down to 1.5Gb . Have looked at all my aps and can't quite narrow it down to:

"we know who stays .. But WHO Goes ????

Have I overlooked a shortcut designed for me to monitor this thru settings? ..?

or has it not occurred to the programmers to add such a timer ?

should be easy to do as all of our network time is captured and each of those captures is shown a site that might have been approved by a certain AP..

there fore attach these saved / along with ID 'd codes to a calculator and voila ..

Looks like I never use the Yelp Ap or one of my three weather aps ... Gone ..

I'd Vote for one .. Is there a site to get this petitioned??