Settings > General > Accessibility > Assistive Touch > On
That is how you access the ability to make a floating home button on your screen.
Is your home button not working correctly on your iPhone? Sometimes 99.99% alcohol can help. Turn your phone off and then put a few drops on the home button. Press down with a cotton swab about ten times and you will see dirt coming up. Wipe it up and this will help relieve a sticky home button.
If this doesn't work you may want to just use this Assistive Touch to allow you to press the home button for you.
I don't particularly care for it because it messes up the look on my iPhone. But if you are desperate then this could help.