Apps with 'Multiplatform Export' feature
Bitwarden is the easiest and safest way to store your logins and passwords across all of your devices (iOS, Android, Chrome, Firefox, Opera, Windows, Mac, Linux, and more). Bitwarden is FREE and open source.
KeePass Cross-Platform Community Edition - A community maintained fork of the popular KeePassX application with more features and frequent updates.
Professional digital photo management software to organize, tag, compare and process photo collections.
GDevelop is an open-source game making software designed to be used by everyone. Any kind of 2D games can be created with it and no programming skills are required to get started. Logic of games are made using visual events.
Gramps is a Free Software Project for Genealogy, offering a professional cross-platform genealogy program, and a wiki open to all.
Armory is an open-source 3D game engine with full Blender integration, turning it into a complete game development tool. The result is a unified workflow from start to finish, making you work faster. No more jumping between different applications.
KLatexFormula is an easy-to-use graphical application for generating images (that you can drag and drop, copy and paste or save to disk) from LaTeX equations. It is written in Qt4.
Orx is an open source, portable, lightweight, plugin-based, data-driven and extremely easy to use 2D-oriented game engine. Orx is mostly written in C, but allows you to develop with it with any language that can interface to C.