This is third-party software that works on any device, and does not require any downloads. It can only post from Google+ to other social networks, including Facebook. It cannot post the other way around. Visit magentariver.com and click Sign Up. SelectSign-Up now! under the Free Plan option. The Free Plan has a three destination-account limit; for instance, you could post Google+ updates to Facebook, Twitter, and Tumblr, but not to a fourth network. The paid versions allow for more accounts and additional features, but try the free version first to make sure you like the system. Follow the prompts to sign in to your Google+ Account on the Magenta River website. Optionally, on the "Magenta River would like to:" screen, you can click the pencil icon to edit its permissions. For example, you can prevent it from viewing the list of people in your circles. Click Accept once you're done. The last screen before activation has two options. Decide whether or not you want to be emailed important updates, and change "Accept Terms of Service" to "Yes." Select Activate Account. Select Add Destination and select "Facebook from the drop-down menu. Click Continue to Facebook, log in to your Facebook account, and click OK for each screen that pops up. When finished, you should be taken back to your Magenta River account.  If you don't see the "Add Destination" option, go to magentariver.com and click My Account in the top right. On one of the confirmation screens, you can change the level of sharing by clicking the icon in the bottom left. For instance, you can have Magenta River post "Publicly" to the internet or "Friend Only." Back at the Magenta River Dashboard, click Link Source to the right of your Facebook account name. In the popup window, make sure your Google+ account is set to "Add," then press Link Accounts. Every post other than private posts will be automatically sent to Facebook. It will take an average of 20 minutes for this to happen, with a maximum of 60 minutes. As you use Google+, Magenta River will track the times you are most active and check your account for new posts more frequently during those times.
Know how Magenta River works. Sign up. Link Magenta River to your Google+ account. Finish activation. Add your Facebook account as a Destination. Link your Facebook and Google+. Post on Google+.