Hello Guys!
So about the thing with people not being able to install the app, that means you do not have SPACE to install the mod. I recommend deleting a couple apps so you can install the mod. If you deleted all the apps and have more space try installing it then. If it does not work it means either you still need to delete more apps or your device just cannot handle it ( I THINK SO)
Please reply if you have any other problems, i'll try to help.