If you have the very latest Android, they have changed the "Swipe-up" on the home screen so it doesn't work like before. Then you have to go into your system settings and change it to "Three-button control". That will add a small square on the bottom left of your screen. Tapping that will act like the old "Swipe up" to show you running apps, which you can then individually swipe up to close. Hope this helps!