How do I activate Notepad+ photo extension? (available only for iOS 8 and higher)

In the Photos app select the image/photo and tap “Edit”. Tap the control with three dots in the screen with edit options. Select Notepad+ icon in the popup to launch the extension.

In case there’s no Notepad+ icon in the popup at once tap “More” and turn the switch next to Notepad+ to ON.

Note: Extension is available for iOS 8 and higher.