Just downloaded App and update firmware on both Oregon 400t and NUVI 3790 using a iMAC 27 with OS X 10.8.2 Mountain Lion. I will say GPS units need to be turned on, using correct UBS for each unit as provided at purchase from Garmin, after Garmin icon comes up open Garmin Updater located in Launchpad. HOWEVER, I was unable to download my life time maps and had to do to my IBM machine for that, 6 downloads, 4 upgrades and 10 hrs later, my maps are current. Hope this helps.Lee J.

I downloaded this app store version thinking that it would find my 3790 Nuvi, but it won't. I rebooted, I tried their communicator plug in, but none of that worked. The old app seems to see my device and download the updates, but they won't install since it then says it can't find the device. My Mac and Safari are fully up to date and I tried it with Chrome. No useful error messages either. I will have to find a PC to update the maps. The device won't mount as a drive like their help pages say either. However, it charges fine from a variety of USB cables that I tried. Those cables work fine for other devices. My TomTom Software works much better for my other GPS unit.Hints For GarminPut some error messages in there so at least people with a clue can do some more work finding out why it might not work.Update you help pages beyond old versions of the OS and browsers. The old updater apps used to work a few months ago.Blame Apple, but, your debugging team should have figured things out and issues an update. I can't be the only Mac user out here.

This is a great app! I have been using it for years from Garmin's website. It lets you update your Garmin GPS software and choose individual updates, including different voices for your device. For newer devices; such as, nüvi 3590LMT, it has been way easier to use this app to update GPS software than Garmin's myDashboard page. I give it 5 stars for its ease-of-use and it does exactly what it says.

I downloaded the app and it updated my 2597in less than a minute. The website took over an hour when I updated it last time. The only complaint is you can not download the extras like voice or car changes with this app.