Flare V1.1 The Lighting Add-On is an HDRI lighting tool for Blender from PlanetBlender. It keeps things simple with just three controls, and it lets you import your favorite HDRIs and save them so they are ready every time you start a new project. The developer notes that free HDRIs are available from sites like hdrihaven.com, so there is no need to buy an add-on packed with images you may never use.
To keep imported HDRIs on hand across projects, you import them and then save a new startup file through Blender's File menu. Version 1.1 adds the option to create categories for your HDRIs, making it easier to find the one you want. The add-on ships with documentation, is offered under a royalty-free license, and has a demo video available. PlanetBlender describes it as a starting point, with further functions planned for future updates.