The Apple programmers liked to open programs or switch between programs to do with animation. And without those phone animations the iphone feels a lot faster.
An option to do so is the “Reduce motion” With this option, you will see fewer animations when you start apps and browsing screens.
This option can be found here : Settings> General > Accessibility> Reduce movement.
iPhone faster with trick over Assistive Touch But a user of Reddit has discovered that you can speed up your iPhone in a different way.
This works as follows:
1: Go to Settings> General> Accessibility.
2: Turn the switch on Assistive Touch on green.
3: Now go back to the home screen by pressing the home button. Drag the Assistive Touch icon as far as possible to the right.
4: Start a Spotlight search by swiping down on the homescreen. Once the Assistive Touch icon is above the keyboard, tap the screen to close Spotlight again. You have to repeat several times until you find the right timing. You will see that Spotlight is suddenly much faster. The trick is now active.
5: Start some apps, to see if there are animations are noticeable. If not, repeat the previous step until you get it working.
6: Then you can disable Assistive Touch. Once you restart the iPone will return the animations. You then have to go through the steps above to turn off the animations.
Below is a video in which everything is explained.