Main screen
After authentication, you are presented the main screen of Check-in Fox. On the top left corner is the menu button, tapping this gives you access to the menu drawer. Most functions - as of now - remain unimplemented, you can access the Help & About sections, and Log Out here.
The Geolocation button
On the top-right corner of the main screen is the Geolocation button: the spinning animated Geolocation button means the device is looking for a precise location (GPS fix), after a precise location is acquired, the icon changes to a stationary, unanimated one and the map on the bottom of the screen is updated to reflect your supposed location. Your geolocation is automatically updated as you travel through the wilds, but you could click this button to manually start a location refresh (this will also result in reloading of the venue list, showing the venues close to your new location).
Your last check in
On the top of the main screen, some details about your last check-in are displayed: when and where were you last seen, according to foursquare.
Venue list and search
Under your last check-in is a search box and a list of venues around your supposed location. You could type any search terms into the search box, and hit enter if you are looking for a specific venue, or click the Refresh button on the right to have the list of venues updated. You could use the Refresh button to load a list of venues when inside buildings, as the app will use your last-known position (before you entered the building, and lost GPS connection) to gather a list of nearby venues. By clicking on a venue in the venue list you are taken to te Check-in screen.
Map
The map displays your current location, according to your device's measurements. As acquiring a GPS fix on current devices may take a significant amount of time, we initially try to determine your approximate location (that is, country and city or area) to show this on the map - as this is derived from your IP address, this might be significantly further from your actual location. When the device has acquired your (more) precise location via GPS, the map is zoomed in at the presumed position where a blip represents your acquired location. You could zoom (pinch-to-zoom) & pan around to navigate the minimap. Tapping the map brings up a full-screen map where you better see your location and surroundings.
Note: map functionality will be significantly increased in coming versions, with full-screen map, displaying of friends and venues around and more.
Checking in
By tapping on a venue in the venue list, you are taken to the check-in screen where you could publish a check-in with optional accompanying shout message and/or photo. If there are any public photos for the selected venue, they are displayed on the top of the screen in a rotating fashion.
Checking in
You could publish a check-in by tapping the highlighted Check in here! button in the center of the screen. You may optionally disclose a shout (short message) via the text box, or attach a photo via the Attach photo button. By clicking the Attach photo button, Firefox OS presents you with multitude of ways to choose the photo - from either the Gallery/Memory Card, or snap one right there with the Camera app. The attached photo is displayed on the bottom of the check-in screen (tap to view full image). If you changed your mind, you could remove the photo with the overlaid Remove button. If you want to share your check-in (and/or shout, photo) with your friends, you may choose to tick one of the share buttons: Share on Facebook and Share on Twitter (or both). If you changed your mind, and decided not to check in, you could tap the back button on the top left corner to return to the main screen. Clicking on the view on foursquare link takes you to the detailed venue page on the foursquare mobile website.
Note: the Add a friend (tagging) button is not avaliable in current version of the application
Post check-in screen
After a successful check-in, the Post check-in screen is displayed, where you could review your results, and the app lists the points you got for this check-in. If you attached a photo to the check-in, it is shown here again as well. Click OK on the Post check-in screen to return to the main screen
Geolocation in Firefox OS
Geolocation in early versions of Firefox OS makes use of the device's (A)GPS sensor. This means, that acquiring a precise location might take significant amount of time, and would probably work only outdoors, with clear view of the sky. This makes it harder for one to use this for such highly location-dependent applications, as foursquare. The cell network & wi-fi based geolocation on Firefox OS devices poses several privacy-related issues - and mozilla traditionally takes privacy very seriously - but is a very actively developed portion of the OS, and is coming to Firefox OS, rather sooner than later.
Setting up geolocation properly
First, you need to set up AGPS APN. You will find this in the device Settings ⇒ AGPS-Settings menu. You should set it to the same value your cell data APN is set to, in Settings ⇒ Data settings ⇒ APN. If you don't know this, you should ask your network/data provider.
Next you need to go outside. Current geolocation on FirefoxOS is GPS-only, which means it won't work indoors, you'll need a clear view on the sky to acquire a GPS fix. You should also turn off Wi-Fi and use cell data, as AGPS won't work on a WiFi connection.
If you did everything well - you are outside, with clear view on the sky and have nailed the setup - your phone should get a GPS lock in under 1-2 minutes - and a precise position. Without AGPS, you might still get a lock, but it could easily take 10+ minutes until your phone acquires GPS lock without network assistance.