Verified now with even old iphone 4s, there is a setting in the systems to put a digital home button back on the phone.

Because yes, I could open up your phone, but I’d rather not if there’s a chance. So try out this great trick.

1. Open settings
2. Got to General>Accessibility
3. Scroll down to either interaction or assistive touch
4. From interaction, find assistive touch and turn it on
5. From the assistive touch pres the > button and turn the button on

Many thanks to Gail who verified this!