You can also tap on the "Find me" button found in the top right of the location bar. When tapped, the application will find your current GPS location and set it as your location. If you don't choose another location after this action, your app will always launch and find your GPS location.
When viewing the map, you can also tap and hold on any location to make that location your selected location.
To delete a location, tap on the selected location at the top of the page. When you are presented the locations page, tap edit, then tap the red icon next to the location you would like to delete.