This was always planned as a feature, and now it's finally here... Hill Bagging!
Basically you can now mark off the hills you've climbed, either singly or multiple hills from the list view. You can set the date you've climbed the hill as well as any notes on the climb. Change the date by pressing the date on the Hill Detail view and enter any notes there, making sure to click the save button. Dates will default to today's date.
Next I'll be working on allowing you to import the hills you've climbed from a file (e.g. csv) and export/backup those hills to the sd card. Hopefully this will help those of you who already maintain your own bagging lists in a spreadsheet.