Flatpak is a solution for creating contained software builds for GNU/Linux systems. You can find more information here.
KDE Software approach to Flatpak is still not ready. Nevertheless, it's being shaped up. If you're interested in helping, please send an e-mail to firstname.lastname@example.org.
The idea behind flatpak is that your applications will depend on a runtime. KDE provides a runtime with Qt and all KDE Frameworks 5 (except for the 4th tier) to make sure it's easily adaptable for any KDE Application and possibly most Qt-based applications as well.
This runtime can be added by following these instructions: [code] flatpak remote-add kde http://distribute.kde.org/testing/ --no-gpg-verify flatpak install kde org.kde.Sdk [/code]
Now you get to compile your favorite application. If you want to see how it's done, you can see some of the ones that have already been built. You can find it here.