Tap Settings > iTunes & App Store > and turn Automatic Downloads off. If you spend a lot of time uploading Music, Apps and Books you might want to turn off those as well. Turn off Background App Refresh. Tap Settings > General > Background App Refresh. read more
Why is your iPhone slow and how to fix it. Wirefly explains why your iPhone can get slow and how to make it run faster. read more
The problem we are talking about here are not Slow Internet connection, rather a slow wifi period. Basically the wifi connection point to point is slow. Nothing related to your provider. read more