To get an evisa you need to show a flight to the country you wish to go to from the country in which you are applying. The evisa is emailed to you..
I dont agree that you need to be a legal resident of the country in which you are applying. I am a Brit and in the last couple of years have got evisas in one shape or another for Oz, NZ, Thailand, Vietnam etc. Nearly all were applied from outside the UK.
If the system works, I welcome this news