Can you add a tip below the big product images that says 'Click to Enlarge' or something similar?
The app has an option to add a tip on mobile. You can set this message on the app preferences page. Just do the following:
- In your Shopify Admin, go to the Apps section
- Find your Cool Image Magnifier
- Tap on Zoom preferences > Scroll down to Mobile Tip
Once there, you can configure it:
You may also add some additional styles to this Tip. That can be done through the "Tip additional styles" field within the advanced options for mobile tip.