The Contacts Journal "Share" options on iOS provide a quick way to add new text, images and files into the CJournal app, from other Apple or 3rd party apps.
There are two types of actions supported by the Contacts Journal "Share Extension" :
- "Add Log": allows you to select text from Mail, Safari or any 3rd-party app, and add that into a Contacts Journal Log
- "Add File": allows you to select files and images from Photos, Files, or any 3rd-party app, and add that into a Contacts Journal "Files" option, for a contact
How to Enable Share Extensions
To enable Share Extensions:
- open the Photos app, and select any photo (you can also use other apps to do this)
- select the Share button 
- in the Share sheet presented, in the list of app icons, select CJournal
If you don't see the CJournal app listed, you might have to scroll to the right, and select "More", and add CJournal to the list from there.
Please note that this screenshot shows how the 'share' sheet looks in iOS13, and will look different in iOS12.
Add Log
Similarly, you can select text from Safari or Mail, and press the Share button, and use this to create a new Log in the CJournal app.
The "Add Log" page will show up, inside Safari, and you can then select one (or multiple) contacts, and change details you want. Press Save when done.
Notes about Share Extensions:
- Share Extensions are available in Contacts Journal v5.0 and above
- Before v5.2, the Share Extensions were split between 2 different extensions, but they have now been combined into one.
- With Share Extensions, you can also save videos from the Apple Photos app, which isn't possible if you use the Contacts Journal app and use the "Import from Photos" option.