PhotoQt is described as 'simple, yet powerful and good looking image viewer, written in Qt, published as open-source, and completely free' and is an app in the Photos & Graphics category. There are more than 25 alternatives to PhotoQt for a variety of platforms, including Windows, Linux, Mac, Xfce and PortableApps.com. The best alternative is IrfanView. It's not free, so if you're looking for a free alternative, you could try nomacs or ImageGlass. Other great apps like PhotoQt are FastStone Image Viewer (Free Personal), XnView (Free Personal), JPEGView (Free, Open Source) and qView (Free, Open Source).
nomacs is a small, fast image viewer able to handle the most common image formats including RAW images. Additionally it is possible to synchronize multiple viewers. A synchronization of viewers running on the same computer or via LAN is possible.
ImageGlass is a simple picture viewer with which you will be able to display your image collection in a very similar way to the one that Windows provides by default, but with some additional functions.
FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor. It has a nice array of features that include image viewing, management, comparison, red-eye removal, emailing, resizing, cropping and color adjustments.
ACDSee is a complex, multi-purpose application that serves for viewing, organizing and editing digital photos. Furthermore, images can be shared on social websites or your own space on the developer’s website.
gThumb is an image viewer and browser for the GNOME Desktop. Features Image Viewer * View single images (including GIF animations). Supported image types are: BMP, JPEG, GIF, PNG, TIFF, ICO, XPM. * View EXIF data attached to JPEG images.