how to get the script to save your username
1)place then script in your Assests folder.
2)Open your login scene.
3)go to your hierarchy Canvas create empty call it "Remember"
4)add the remember.cs script to it.
5)input text = inputField_Username->Text
input field =inputField_Username
textfield =inputField_Username->Placeholder
Toggle is your togle checkbox
6)have to go to the Hierarchy enebo Toggle botton
and you done ).
if you still have problem use this file has the Scrip and the Scene to Login all the work is done use this Scene to Login.
http://www.mediafire.com/file/v82kvmgpdo3lo7f/Login.unitypackage