The two biggest problems plaguing most iPhone owners are the twin desires for more battery life and more storage space -- at least, those are my top two. What if you could kill both birds with one not-too-heavy accessory?
The Mophie Space Pack does, indeed, offer up both: a full-charge battery case, with 16 or 32GB of extra flash storage thrown right in. Sound like the best iPhone-as-camera accessory ever made? It very nearly is, if you can accept a high price and some limitations.
The Space Pack looks like and performs like Mophie's other iPhone 5/5S battery-pack cases: it's a bit thicker than the Juice Pack Air, but has the same 1,700mAh battery. Stick some extra storage in there, and you have the idea. At $149.99 for the 16GB Space Pack or $179.99 for the 32GB model, it's a pretty expensive iPhone case, but it amounts to either $50 or $80 more than what the $99 Juice Pack Air costs anyway. Expanding your iPhone's storage from 16 to 32GB costs $100 anyway, so $149.99 for a battery pack and 16GB isn't such a bad proposition, even if Android owners with microSD cards end up laughing. If I were buying one, I'd pony up the extra $30 for 32GB. The Space Pack comes in black or white. My review unit, a 16GB model, is white: it's glossy, and snapped on the iPhone easily, but like other Juice Pack cases you need to run a headphone jack extender to listen to music while using it.
The case feels as good as any other Mophie Juice Pack, and a silver button on the back activates the onboard storage access. The Mophie Space App, free on the App Store, is required to access any of the files stored on the Space Pack, much in the same way that other wireless storage drives from SanDisk and others work. But the Space App has a clean flat design that feels like a good match for the rest of iOS 7.
Getting files onto the Space Pack is exceedingly easy: it works like a regular USB flash drive or hard drive. The Space Pack charges via Micro-USB, and you can plug that cable into a PC and drag and drop files into a folders the way you'd expect to. You can put anything on -- music, videos, ZIP files, even EXE files. They won't all be readable on the Space App, but the fact that the Space Pack's storage can be a hybrid of USB drive and iPhone storage extension is actually pretty useful.
The Space App automatically organizes files into Photos, Videos, Music, Documents, and "other files." Documents open in read-only format on the Space App, but can be opened into other apps, like Google Drive, if they're on your phone. Music files play on the app but can't be imported into the iOS 7 Music app. Video files need to be DRM-free: iTunes purchases can't be stored on the Space Pack. And, not all video files will play back: I had success with M4V and MOV files, but not AVI. (According to Mophie, you could open an AVI in a third-party app, but it won't transfer unless it's under 100MB in size.) The Space Pack supports a lot of formats, though, mirroring the iPhone's playback capabilities: MOV, MP4, M4V, 3GP, MP2, MPA, MPE, MPEG, MPG, MPV2, QT, LSF, LSX, ASF, ASR, ASX, and MOVIE.
It's the Space Pack's photo-syncing feature that's the real killer app: you can sync your photo and home video library to the Space Pack's storage and offload those files from your iPhone's main memory, freeing up space on the go. For people on long vacations, using the iPhone 5 or 5S as their main camera, it could be a lifesaver. Files can also be shared via AirPlay or AirDrop, in theory, but I haven't had much success with that yet.
I use my iPhone 5S as my main camera most of the time. Maybe the Space Pack is the killer accessory I've been looking for. I'll be taking it on a week of testing, so stay tuned for a full review.