I've been using the OIShare App with my OM-D E-M10 for a while but never really considered the Geotagging function. As we were doing a road trip around France I thought it might be fun to try it out and work out where we'd been and refresh my memory when I'm looking back at the images later. I couldn't find all the answers to my questions before we went so I thought I'd document my experience for others to find. The App uses location services on your phone to keep track of where you are. Later when you connect the camera the App adds location information to the pictures you took. The OIShare App is here ... OLYMPUS Image Share (Smartphone app) | Olympus Imaging Getting started... Sync the camera and phone clocks. Start the camera WiFi connection, Connect the phone to the camera WiFi, then open the App to sync the clock on the camera to the phone. You don't have to "do" anything other than connect and start the App, there's no button. This allows the App to work out where you took your pictures later by comparing timestamps from photo to the log. You don't need to keep them connected, even when you're taking pictures. I didn't deliberately sync the camera/phone clock every day but I did transfer photos and logs each day so they didn't have much time to drift. Location services The App needs to be granted permission to access your location (obviously ). The App needs to keep running to log your location (obviously) but doesn't have to be running in the foreground, you can make calls, use maps etc. as long as you don't turn it off. If you do turn it off or you flatten your battery the current log is still saved. Starting and stopping GPS logging In the App and turn on "Add Geotag" by flicking the switch on the App home screen. This starts a new Log (accessed by pressing that whole menu button). Flip the switch on the App home screen again to turn off logging, next time you turn it on you get a new file. Your GPS journey If you're on WiFi or data then your current position is overlaid on a map of the area in the app. If you have location info for a while you can see a trail on the map of where you've been which is . You can't see this if you don't have an internet connection i.e. if you're connected to the phone. Adding Geotags to images. Connect the phone to the camera WiFi and open the app. It will prompt you to add geotags and warn you it make take a while. You don't have to do this, it will try again next time you connect up. The App keeps track of what has been updated though it did seem to retag some images. Geotagged images show a little satellite symbol when reviewed on the camera. You can switch cards and tag, they don't have to be updated in the sequence you shot. GPS info. The GPS info is added to the individual image files and the GPS log is also saved on the SD card in it's own folder. They're just plain text files with a .log extension - my smallest is 5KB my largest 2275KB - 14MB in 3 weeks vs about 40GB of pictures so no real impact on storage. You can email GPS logs from the app which I did along with backing up my SD cards each evening. The GPS is visible in the EXIF data for the JPG and embedded in the .ORF (RAW) file, visible in Olympus Viewer 3 and is exported when you save a JPG from ORF in Lightroom. Flickr My tips: Phone Battery Life Using GPS all the time wallops the battery on your phone. I was using NavMii and Google Maps a lot too but really noticed the extra drain. I normally finish the day with 20-25% but was down to single digits if I didn't top up. I didn't run out during the day but I did manage to flatten my phone overnight when I forgot to plug it in and left it logging. It doesn't restart logging if you restart the phone or the App unless you open the App and start it again manually. Location services Location services were set to "Always" by default. This meant OIShare kept GPS running even when it wasn't actually logging unless I closed it by double clicking the phone home button and swiping the App away I've since set it to "While using" but it's still worth checking if you see the triangle up by the battery indicator especially if you don't think you're using logging. Turn it on! Try and remember to set the logging running . I missed tagging a few images as I'd switched it off to save phone battery and forgot Tagging I discovered if I was still logging when I added geotags with the camera and phone connected it took substantially longer than if I stopped logging first. Camera location vs. Phone location If you take your camera with you and leave your phone behind, the images will be GPS tagged with the location of your phone. I'm as likely to leave my phone behind as I am to leave the house naked, but if you leave it in the car at the beach and go for a long walk with your camera, you won't get good GPS data GPS log file I don't know if the file format is universal - I've attached one (with a .txt extension) in case anyone with more knowledge wants to take a look. As the App is free it might be useful to non-Olympus users too.