IOS Apps in iTunes - how to tell latest version?

Question

I'm trying to find out which of my iOS apps haven't been updated in, say, the last three years. There are 4 date columns available in the View Options:
Date Added, Date Modified, Purchase Date, and Release Date. As far as I can tell this is what each one denotes:
Date Added: the date I first purchased the app.
Date Modified: the date I downloaded the latest version
Purchase Date: the date I "purchased" the latest version
Release Date: the date the very first version was added to the App Store
So the second & third dates are identical for the vast majority of my apps, but a few have wildly oddball dates. For example, one has the 2009 date I first purchased the app under the Purchase Date column instead of the Date Added column. Also the 2014 date that is in the Date Added column is in the Date Modified column (even though it is one that I KNOW hasn't been updated since 2009).
So which is the correct column to use in determining how old is the app version I have installed? I'm thinking either the Date Modified or Purchase Date columns would work, but there are the few apps where the dates in those two columns DON'T match. Suggestions?

Answer 1

When I go to iTunes preferences under the Devices tab, there is a date and time for my iPhone's backup - next to the name for my iPhone.
Where are you looking for this?
Just wondering because I had some important pictures I took on the phone and want them saved just incase my phone starts acting up again.
Photos captured by your iPhone should be imported by your computer as with any other digital camera. Have you ever used a digital camera before? If so, did you leave all photos captured by your digital camera on the digital camera - you never imported the photos from the camera by your computer so the photos were stored and available on your computer for viewing or for sending via email or whatever? If you did, why would photos captured by your iPhone be treated any differently?
You should always import these photos by your computer - as with any other digital camera. It isn't a good idea to depend on your iPhone's backup alone for these photos.