This is not a problem. The iPad screens are made with LED screens, which do not get damaged from staying on long times.

Old CRT screens had a problem that images could "burn" into the screen. This does not happen with LED screens.

However, it is good to "exercise" LED crystals regularly. That's why we designed the Photo Display app to rotate between a number of photos.

Also, the app has a "Dark Screen" feature, where you can darken the screen during certain hours. This is useful if the screen light is disturbing your sleep or lifestyle.

iOS has a feature called Guided Access, where you can restrict access to a single app.

Turn on Guided Access by triple-clicking on the Home button. You may have to turn on Guided Access in the iOS Settings -> General -> Accessibility -> Guided Access.

When Guided Access is turned on it is impossible to switch to another app.

The photo frame reads photos from an album in your iCloud photo library. So if you add a new photo to the album on another device the photo automatically syncs to your photo frame as soon as your Photos app sync to iCloud.

Your device automatically syncs photos with iCloud with regular intervals. It normally takes just a few minutes, but it could take up to an hour.

You can force a sync by opening the Photos app. Once it has synced you can switch back to Photo Display, the new photos are automatically picked up.

Yes, you can easily give access to friends. Open the Photos app and create an iCloud sharing album. Share the albume with your friends.

When your friend adds a photo to the album it automatically syncs to the photo frame.

There is no limit how many photos you can show in an album.

Open the Photo Display app and tap the screen to show the toolbar. Click the settings icon in the lower right corner.

In the settings you can change the duration for the photos by changing the slider.

The photos load from your Photos app on the device. If the full size photos are not on your device they need to get loaded from iCloud. This could take a while, depending on your Internet connection.

You may also see low-res photos if you click forward through your photos really quick, as it can take a second for the app to load the photos from memory.

The app itself uses very little power, so it really depends on the screen brightness and the quality of your battery.

Normally you can run Photo Display for 6 to 12 hours before you need to recharge.