I'm not sure of the format on mobile, but on PC there should be an arrow pointing down near your name in the upper banner. If you click that a drop down menu will appear. Select 'My Purchases' on the menu. That will open a new page with a list of all the games you've bought and have a button that says Download under each game. Clicking the download button will take you right back to the original download page where you can get it again :].