Once you've completed the python course, is there any way to get better when offline?
You can also suggest applications that can work for me
Yes, you can ! Go to Home page>courses> You will find all the courses that you are learning click on the right 3 dots of that particular course which you want to make available for offline and download it. It will be available if you just start that course ,it's not mandatory to complete to get that offline.
you could try codecademy go