FLARED IS A REAL-TIME LENS FLARE GENERATOR THAT WORKS DIRECTLY IN THE VIEWPORT OF BLENDER.
So you can have a direct preview of the final result without the need to use the compositor.
It's not screen space-based, so it works also when light sources move out of the screen.
Flared is based on EEVEE, but there's Cycles support too ( please take the time to watch this video if you want to use Flared in Cycles, because it shows how it works in Cycles, through the compositor: there's no native support, for now ).
It takes advantage of procedural materials, so it's resolution-independent. It's easy to use and customize and can help you to add cinematic looks to your 3D scenes or give more drama to your real video footages.
Flared it's not a physical simulation of the light path through the lens, it's a powerful artistic instrument, highly customizable (you can save your presets and use them in other scenes).
You can add several flares with just one click, choosing from different templates.
Flared can setup and add lens dirt too.
With the slider called Obstacle/Occlusion you can manage how fast the flare disappears behind obstacles (this action requires manual keyframes).
Flared can be used both with CGI scenes and video footage (it's possible to link the flare to an empty created with the motion tracking skills of Blender).
You can even add a Sun where it's missing!
Flared has been on sale for 18 months. During this period, we had time to test and improve it. Here is the full Tutorial: watch it if you want to see how Flared works before making your choice!
You can find more details on the official website.
* The 3D scenes of this presentation come from https://www.blender.org/download/demo-files/
and they have been used only for testing purposes. The video footages come from https://pixabay.com. Credits go to the authors.