Install older version of app

Hey everyone, I was wondering if I could reinstall an older version of an app on my iPhone 6s? The app recently updated to a version that isn't very good in my opinion and I would like to revert to the previous version that I used to have. I have the older version on my iPhone 5 because the update isn't available for the 5. Is there any way I could transfer the app from the 5 to the 6s? Thanks