Thanks for this great suggestion, we'll look into this. I've added it to our Feature Requests list (number 84), where anyone interested in it can vote for it.
Currently, in order to upload my existing route for editing, I have to use the desktop mode of the browser, which is very difficult from my smartphone. Adding this functionality will greatly enhance the value and ability to modify route on the go without having to bring tablet or notebook. Thanks.
DESKTOP TABLET MOBILE
(no app download required)