You can add any of the four Day One widgets on the Today View on iOS.
The options are Activity Feed, Nearby Entries, On This Day, and Usage Stats. Tap the Edit button at the very bottom of the Today View to customize your widgets.
This widget shows your recent locations. Tap the checkmark icon to create an entry with that location. Tap "Show More" at the top right to see more locations.
Tap the pencil icon to edit that entry in Day One.
This widget shows the Daily Prompt. Tap this to open Day One with the prompt set as a header.
On This Day
This widget shows entries from the current date in the past. Tap "Show More" at the top right to expand up to 12 entries. Tap any of these to open directly to that entry in Day One.
This widget shows a graph of your data for the past 50 days. Tap the widget to cycle through views for entries, words, or photos per day.