One thing that I had to face and discuss at least once a month among Clients requests was: an easy way to paste images into SharePoint pages. Although my automatic answer was always “Just upload it through the ribbon, so you can tag and ensure the content quality”, I have to admit this way isn’t THAT user-friendly.
But if your prefer, it’s possible to add those scripts into your Master Page files, so you don’t need the Provider-hosted App approach.
Copying the image
The functionality will be installed and attached to the Body fields on your pages. So you can just copy an image from your photo viewer or editor.
Pasting the image
Just focus the cursor in the the body of your Page and paste it: