Recent Scrollshot Widget
Recent Scrollshot widget requires you to enable it manually in Notification Center.
1 Find Edit button in the bottom of Today page in Notification Center.
2 Find Recent Scrollshot in the list, tap the + button on the left side, then tap Done.
3 After you manually take screenshots in sequence, the widget will recognize and automatically stitch them together. If stitch succeed, you can save the long screenshot in widget directly.