How to Reduce size (not .ipa) for iOS?

I am trying to submit a build to itunes connect, so that I can use the testflight for external testing. I had to add 64 bit support, in order to be able to submit. (As of Feb2015, that’s apple requirement.) Once I did that (not the .ipa size) went over 80MB to around 102MB. I get this error on application loader that the maximum size of .app must be less than 80MB, and can not exceed that.

How can I reduce the size of What does that file actually include? Does disabling plugin-ins help?