Answer 1

If you are asking to upload some code of your own... In my case I do so from my PC not the cellphone (easier that way).
Google sololearn and once inside -> codeplayground -> add new code -> copy/paste your code and save it.
Then I come to my cellphone, look for the post where I ll paste it (since they dont show up in the browser version), add it by tapping the '+' button.
Hope that helps!