This application allows you to create an image based on a bunch of other images. It looks like a mosaic effect.
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.
Deepin Image Viewer
A simple Image Viewer
Viewnior
Viewnior is a fast and simple image viewer for GNU/Linux.
KSnip
Ksnip is a Qt based cross-platform screenshot tool that provides many annotation features for your screenshots.
GottenGeography
An easy to use geotagging application for the GNOME desktop, which aims to have a very streamlined and intuitive interface that makes it easy to apply geotags to photographs.
Rottuleit
BitTorrent P2P multi-platform search engine for Desktop and Web servers with integrated torrent client.
Deepin Draw
Lightweight and simple drawing tool
Myrkraborð
darktable is an open source photography workflow application and raw developer
aMule
aMule is an eMule-like client for the eD2k and Kademlia networks, supporting multiple platforms.
Currently aMule (officially) supports a wide variety of platforms and operating systems, being compatible with more than 60 different hardware+OS configurations.
aMule is entirely free, its sourcecode released under the GPL just like eMule, and includes no adware or spyware as is often found in proprietary P2P applications.