Burbn’s popular photo-sharing app Instagram (free) has added video in version 4.0. The addition will provoke comparisons to Vine, but the two are much different: Instagram video lets users take video clips as long as 15 seconds, and 13 video filters are also available. Videos notably do not loop, as they do in Vine. Cinema, an image stabilization feature, is available for those using the app on an iPhone 4S or 5.

Lytro, maker of the Lytro Light Field Camera, has released a Lytro (free) app for iOS. The company has awakened the camera’s hitherto-unknown Wi-Fi capabilities in order to interact with the app, letting users share photos to Facebook and Twitter. Lytro’s app also lets users save photos as animated GIFs that can be emailed or sent via text. The Lytro Light Field Camera lets users refocus pictures after they’re taken, and allows interactive “living pictures” to be refocused endlessly—a neat technology that our editors felt wasn’t ready for prime time after testing the camera.

Gameloft’s Modern Combat 4 Zero Hour ($7) has added three new maps — Barcelona Train Station, Antarctica Research Facility, and Barcelona Streets — in version 1.1, which is billed as the Meltdown update. Likely to choke when installing over Wi-Fi on an otherwise filled iOS device, the massive update also features a new “demolition” specialization, two new weapons, and two new team multiplayer modes. Signatures can also now be edited to display a clan prefix.

Attracting at least as much attention for its unusually high App Store asking price as its well-known name, XCOM: Enemy Unknown ($20) is a $40 console tactical RPG that just happens to run on iOS devices—mostly. Based on Unreal Engine 3 technology, the sci-fi-influenced XCOM places you in control of squads of soldiers as they confront invading aliens in close-quarter locations scattered throughout the world. You take up to two turns moving each soldier and using weapons to fight the aliens, with everything from isometric perspective maps to gun battles and cinematic sequences presented within a dynamic, highly detailed 3-D engine. Full voice narration and music keep the energy level up as you tap-select safe positions on each battlefield, engage the aliens in stat-based combat, and continue to exchange rounds until only one side is left standing. Post-battle headquarter sequences let you power up individual soldiers, choose from different missions, and learn more about the enemies you’re facing.

While owners of the fourth-generation iPad will find XCOM’s 3-D performance to be respectably comparable to a console or low-end PC gaming experience, frame rates and resolution drop pretty dramatically on lower-end iOS devices; for instance, the iPad mini’s in-game sequences are all still playable, but otherwise impressively complex cinematics and other camera transitions stutter quite a bit. We’ll have to see whether post-release tweaks improve XCOM’s performance, but given that the turn-based action doesn’t require twitch responses, what’s here is good enough for the time being; the interesting levels and strategic challenges are the stars of this show.