GOOD MOVIES can sometimes give off a hum—a feeling that the energy and chemistry on screen can't be constrained by the edges of the frame. Tangerine, the latest from co-writer/director Sean Baker (Starlet), fits this description and then some, creating a kinetic rush with enough spillover juice to light up LA for a year. While chockfull of innovations both welcome (a story about transgender characters, played by transgender performers) and potentially eye-strainingly worrisome (the movie was shot entirely on tricked-out, stabilized iPhones), the main takeaway is just how alive it seems.

Following a delightfully chintzy credit sequence, the story finds friends and street-corner business associates Sin-Dee (Kitana Kiki Rodriguez) and Alexandra (Mya Taylor) reuniting on Christmas Eve after the former returns from a stint behind bars. The pleasant chitchat ends, however, with the accidental revelation that Sin-Dee's boyfriend/pimp has taken up with a cisgender woman. And off Sin-Dee goes, stomping toward the offending "fish" with a hilarious single-mindedness that puts the demon in It Follows to shame. As the more levelheaded Alexandra alternates between giving chase and fulfilling her own holiday plans, a lovestruck cab driver (Karren Karagulian) with some very specific tastes gets drawn into the whirlwind.

Viewers wary of YouTube may have some understandable qualms about Tangerine's reliance on camera phones, the presence of which has served to undercut some of the film's thunderous festival buzz. Once in play, though, their use seems less like a gimmick and more like the only way possible to keep up with the perpetual motion of the performers. While somehow managing to be always in the right position at just the right time, Baker and his DP (the wonderfully named Radium Cheung) brilliantly make the limitations work for them, concocting a delirious, nuclear-hued glow that captures the aura of Los Angeles in a way few movies can. The reason for the title becomes apparent within the first few moments.

The film's unpredictable, caffeinated vibe is only enhanced by the largely untrained cast. Grabbing the spotlight with her opening line, Rodriguez makes for a funny/sad force of nature, amplified by the random moments of compassion that come burbling through her cranked-to-11 delivery. Taylor, by contrast, may have less scenery to chew, but delivers a gargantuan dose of personality. (Her scene with a penny-pinching client provides the movie's biggest belly laugh.) As the transgressor responsible for all of this chaos, meanwhile, Mickey O'Hagan proves to be a terrific comedic foil, going full skrank with an absolute lack of vanity. Even when she's at her worst, she illustrates the movie's resolutely nonjudgmental nature.

Peaks can only last so long, and admittedly, Tangerine gets pretty maudlin in its last 20 minutes, as the characters dogpile up in the confined space of a doughnut shop and reality begins creeping in. Baker & Co. rebound in a big way, however, with a final, lovely gesture between the two leads that reaffirms their connection and further illustrates the wonderfully unstable molecules that the film can seemingly fire off at will. Without ever seeming to sweat, Tangerine conjures up a world where an illegal business transaction in a carwash can somehow come off as silly, raw, and touching all at once. After the credits roll, the dizzy crackle remains.