An Image gallery application.
FotoQt
PhotoQt is an image viewer that provides a simple and uncluttered interface. Yet, hidden beneath the surface awaits a large array of features.
Gwenview
Gwenview is a fast and easy to use image viewer by KDE, ideal for browsing and displaying a collection of images.
Gnome Photos
Access, organize and share your photos on GNOME. A simple and elegant replacement for using a file manager to deal with photos. Enhance, crop and edit in a snap. Seamless cloud integration is offered through GNOME Online Accounts.
KPhotoAlbum
If you have hundreds or even thousands of images on your hard drive, it becomes impossible to remember the story behind every single image or the names of the persons photographed. KPhotoAlbum was created to help you describe your images and then search the big pile of pictures quickly and efficiently.
Shotwell
Shotwell is a personal photo manager.