To delete an entry you've made, Click on the cog at top right within the widget that contains the entry.
Click "Show All Data."
Simply click on the entry you wish to delete.
A details screen will appear. At bottom, you can click on "Delete Entry". You can also choose to edit the entry by clicking on the pencil icon at top right.
After editing, click "Save", at top right. Click "Back" to exit this screen, and your changes will be saved.