If you want to delete a scorecard, throw, disc, player, etc. do the following:
iOS:
1.) From the More Tab (far right) select Scorecards/Throws/Discs/Players.
2.) Swipe across the row you wish to delete
Android:
1.) From the More Tab (far right) select Scorecards/Throws/Discs/Players.
2.) Long press on the row until it's highlighted. Tap the Delete button. Note: throws/discs support selecting multiple rows to delete at the same time, if you desire.