App on my other devices are still showing as free after I paid

When the application is installed on multiple devices, you have to make sure that you are logging in with the same credential that you have used for your upgraded account.  If you already created a new free account by accident, just go to the "options" menu (the gear button on the top/right corner) and scroll all the way down until you see the "Logout" button. Click the Logout button and then sign in again with the credentials that linked to your paid account.