The camera app is quite basic, it has separate photo and video modes and can store geotagging information but that's it. If the hardware supports it, the Firefox OS camera can do Continuous autofocus too.
The UI has an interesting feature - it shows the photos you've snapped since you started the camera as a film strip on the left of the screen. Those are cleared when you exit the app. Tapping a photo thumbnail opens it in the gallery, there's an additional gallery shortcut below the on-screen shutter key.
The Gallery app is fairly basic - it displays a grid of thumbnails, sorted by month, with shortcuts to the camera and multi-select mode. You can delete or share photos one by one or in bulk.
Viewing a photo adds the option to edit photos but the editor is pretty barebones. It can adjust the brightness of an image, crop, apply color effects or do an automatic enhancement. Basics like rotation, contrast adjustment, sharpening and so on are not available.
Like the Camera and Gallery, the multimedia apps of Firefox OS provide the basic functionality and little else. The Music player sorts your library by artist or album, it also supports playlists including several automatically generated (recently added, most/least played, highest rated).
Album art covers most of the now playing interface, the only options here besides the regular playback controls are repeat and shuffle toggles, plus a rating bar for the track.
While the music player is on there are controls on the lockscreen and in the notification area.
There's no DLNA support or an equalizer.
The FM radio, if available on your hardware, has a simple but fairly unintuitive UI. You can star your favorite stations, they will appear in a list starting at the bottom of the screen. This list lets you quickly switch between them but be careful to tap on the frequency text as tapping on the star next to it will remove the station from the list.
There's no RDS support but the radio can play through the loudspeaker (you still need to have the headphones connected, their cable is the antenna). Note that lack of RDS could be due to the hardware.
The video player interface lists available videos sorted by date, just like the gallery. Once again you get the option to mass delete files or share several at once.
Codec support will obviously heavily depend on the hardware that Firefox OS is running on. The ZTE Open C we used for this review handled sub-HD MP4 files but that was it (some had issues with the sound).
Firefox OS supports dual-SIM, dual-standby connectivity as mentioned earlier but there are no such devices yet. Support was added only recently with version 1.3 but given the platform's focus on developing markets dual-SIM phones can't be far away.
Wi-Fi features include Wi-Fi Direct for file transfers and hotspot functionality. Firefox phones can also share their internet connections with a PC via the USB port.
Bluetooth is supported all the way to version 4.0 and it's possible to send files over Bluetooth (that took certain OSes more than one major generation). NFC is also supported for easy paring.
The USB port on Firefox phones is used for data transfers with a computer too. It connects in mass storage mode, making file management quite easy. Practically all recent Android phones use MTP, which doesn't work as smoothly.
This, however, means that apps can't access the phone's storage while it's hooked up to a computer. The internal memory and the microSD card have separate options for USB sharing so you can connect only the one you need and leave the other available to apps.
Firefox OS uses the eponymous browser, which is a key part of the platform. Unlike its desktop and Android versions, however, the browser does not yet support add-ons, which is a Firefox staple.
The interface is streamlined and it looks just like the Android version of the browser. There's an URL bar on top with the tab switcher in the top right corner (it shows the number of open tabs). The bottom row of the screen shows the basic controls - Back, Forward, Share and Favorite.
New tabs show thumbnails with recently visited sites, but there's no option to remove unwanted ones.
The browser lacks many other features too - there are no incognito tabs, no find on page, no saving pages for offline use, no Flash support, not even an option to sync open tabs with other devices (the Android app has it).
The only options in the Settings menu are clear browsing history and cookies.
Overall we were pretty disappointed as the Firefox OS browser feels undercooked - the Mozilla team already has a feature-rich mobile app for Android, while this one lacks key features.