Flare for the iPhone is an interesting app for video hobbyists, notable for the technical wizardry on display. It can shoot video with a quasi-HDR effect and do it in real time. It isn't easy to apply filtering effects on the fly, and that's just what Flare does.
Flare is not shooting real HDR. You're not acquiring concurrent video streams of multiple exposures. What you are getting is some extreme filtering, sharpening and contrast expansion that gives you a hyper-saturated picture. Some will love the effect. Others might just scratch their heads.
The app gives you some switchable settings to determine how extreme the processing is. You can lock white balance, exposure and focus with two quick screen taps. AirPlay is supported. You're not going to get full HD on the iPhone. Expect 640 x 360 resolution at 24 frames per second on an iPhone 4 and 16 frames per second on a 3GS. I noticed a couple of video stutters on my iPhone 4, but generally the app ran well.
Flare is clever and not overpriced at US$0.99. It's an impressive achievement in software coding. Getting real-time video processing on a cell phone is not a walk in the park. If you like the effects, I'd say go for it, but don't expect real HDR quality. It's just beyond the scope of the iPhone hardware/software capabilities. On the other hand, if you're looking for some stunning, juiced-up video, Flare might be for you.
I've put a few samples in the gallery, and as always, your comments are appreciated. Note that the screen grabs are not as good a resolution as what you can expect in the real world. Flare requires iOS 4.1 or greater.