TwinViewer is a dual-screen photo viewer application.

You can view two different albums simultaneously, compare two photos side by side, pick a better shot, or leave one and delete another.
This is more than just a viewer. You can also create side-by-side combined images, get the detailed EXIF data, etc.

----- HOW TO USE -----

- Swipe left/right to browse next/previous photo.
- Pinch open/close with two fingers to zoom in/out.
- Double tap either one to display in full-screen mode.
- Sync/Async button to switch the sync mode between two viewers.
- Swap button to switch two viewers.
- Grid button to show/hide grid liens.
- Data button to show/hide data such as image size or shooting date.
- Export button to created and share side-by-side images.

----- WHAT'S FULL VERSION? -----

If you upgrade to the full version by in-app purchase, the following restrictions will be unlocked.

・Create and save side-by-side combined images.
・Display image metadata.
・Remove full screen Ads.

What’s New

Version 10.8

- Added Sort Key Options.

Ratings and Reviews

4.2 out of 5
9 Ratings

9 Ratings

rarelyposter ,

Great little app. (Update)

I’m a photographer and retoucher. So it’s nice to be able to compare the original photo with the retouched photo.

After the response from the developer I found the exact feature I was looking for. I missed the instruction in the beginning! My mistake! Being able to tap to quickly switch back and forth between the photos so I can easily see what has been changed. Perfect! Paid for the full version after finding this out!

I guess another neat feature would be if there was also an option to have a slider to compare photos. Where you could slide to your finger back and forth and reveal the second image. Similar to the app “Photo Compare.” This would be a really cool way to compare images.

But the app is already wonderful! This is exactly what I’ve been looking for! ありがとうございました!素敵なアップです!

Developer Response ,

Thank you for your feedback. I'm sorry for the insufficient usage information. The app already has the function. Double-tap either one of photos to see it on full screen. Tap it to switch. Long-press to switch quickly. You can see more help in Information page. I hope it would suit your needs. ;)

rk54 ,

Great support from developer!

First, the app is terrific. I use it to compare images that can be used as examples that show complementary or dissonate differences for teaching. The ability to save as a combined image with captions is just what I needed. And who knows, I could use it to create the next “woman screaming at the cat” meme.
Second, the developer is super-responsive. I emailed a suggestion about Sort Order and in less than 3 days, the app was updated!

cmhawke ,

Best tool for comparing images

Best tool for comparing images that I've used; more convenient and quicker than using the layer method in the typical photo editor. Would be perfect if Recently Deleted were an available folder on the menu but given that most apps don't have that, I'm not complaining! Thanks so much!

Developer Response ,

Thank you for your encouraging comments and I'm sorry I could not meet all your requests.


Masako Sakanashi
15.5 MB

Requires iOS 12.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, French, Japanese

Age Rating
In-App Purchases
  1. Full Version $2.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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