Those are from the Google+ app running on the iPad and iPhone. It's running a modified Chrome browser.
The mention of Mozilla/5.0 has to do with the history of User Agent Strings, and nothing to do with who built the software. See more here: http://webaim.org/blog/user-agent-string-history/
No. Mobile Safari is the only browser that has ever been offered by Apple for iOS.
There are third-party browsers, but even those are required to use the core iOS WebKit rendering engine. The differences they provide are primarily UI-oriented, or things like a "private browsing" mode.
Here is an easy way to manually override the EXIF rotation metadata, if the image is saved in the correct orientation in MS Windows. In Windows Explorer, right-click on the image file and select "Rotate clockwise". Do this 4 times to rotate the image all the way around, and then the image will have the correct orientation for all systems. Then you can ...
I had this issue on two different servers, meaning if you have apache 2.4.8 or greater use this settings in your config file.
Version's 2.4.7 or less
If you're coding with PHP, you could use $_SERVER['HTTP_USER_AGENT'] for checking the UserAgent header, which is sent almost by any major mobile device to PHP script. Then just compare the value of this header with substr fuction to whatever it needs to have inside.
For example, Apple devices will always have 'iphone' or 'ipad' sub-strings; Android devices ...