In order to do this you need to use google chrome browser while using google+ and need to install an extension called Start G+ which lets you post google+ update on facebook and twitter both. Follow the procedure given below to do it.
Start Google+ is designed to help you jump right in to Google’s new social network.
Below are few things that the plugin can do:
1. Put your Facebook and Twitter streams inside your Google Plus stream, complete with "Stream" links on the side and rich media
2. Automatically post to Facebook AND Twitter whenever you share something on Google Plus (you can turn this on/off from within the share window in Google Plus – see the screenshots)
3. Add a Gmail inbox notifier to the top bar, so that you do not have to keep a gmail tab open. Clicking on the Gmail icon shows a menu with the unread messages that let you access your emails directly inside Google+.
1. Firstly run google chrome and then install Start G+ from here
2. Go to plus.google.com, once install you will see facebook and twitter icon which you can check for any update to post them on twitter and facebook as shown in the image below.
3. But now you will need to login and allow authorization to this extension on twitter and facebook both, you will need to login through the extension icon which will be added to google+ bar on the top right as shown in the image below.
Now it will show you twitter and facebook one time authorization screen as shown in the screenshot we took at the time of facebook authorization.
If you are not logged to twitter or facebook when you try to post a google+ update you will see the following error.
So, please make sure you are logged and authorized the extension by connecting to your twitter and facebook account. We also took the screenshot of the updates which gets posted on twitter and facebook, checkout the images below as a proof of this extension works.
Posted Update On Twitter
Posted Update On Facebook
[ Via Compixels ]