LG isn't done creating intrigue at the FCC just because the E980 has made the rounds. A second device, the LS720, has popped up at the agency. Don't expect the same kind of telltale clues that might have given away its AT&T cousin, however -- we mostly know that it's a phone with Sprint-friendly LTE bands, and browser strings suggest that it could ship with Jelly Bean. Is it a sequel to the Optimus Slider (LS700) for Virgin Mobile? A spiritual successor to the Viper 4G LTE? It's difficult to tell at this stage, although the numbering scheme points to something below LG's 800- and 900-series devices like the Mach (LS860) and Optimus G (LS970). We'll keep our eyes peeled.