... for desktop applications.
I'm running openSuse LEAP on my workstation and sometimes I have to struggle to get recent versions of some program to work. Recently I had to fight with two applications, with only minor success: Steam and GIMP.
Probably I'm not the only one who occasionally find itself trapped in a dilemma here. It's a clash of two different philosophies: On one hand on my workstation I want to have a rather stable distribution (thus LEAP, on my Laptop I run Tumbleweed), on the other hand I'm using certain programs, that only come in outdated packages (Gimp 2.8!!1!) or have some issues with outdated libraries ecc. e.g. Steam works nicely with some games, others like Civilization Beyond Earth do not work at all.
Flatpak solves this issue here: It delivers a piece of software including all dependencies and stuff. It's thus able to decouple a single program from the system dependencies. This solved the above mentioned clash: The bare system can be a rather conservative and stable one, and you still can run a very recent version of your program, without going through the nightmare of a dependency hell.
Gimp 2.10 for instance can be installed in two lines and just works, whereas I spend an awful lot of time to get it running as native application with unsolvable dependency conflicts at the end. It was running some time ago, but then for some reason it broke. That's not what stable is about.
flatpak install org.gimp.GIMP
That one installs it and it just runs. And that's pretty neat.