How to autopost from Twitter to Google+
Google+ has been around for about six months, but there are still no APIs with writing permissions. Because of this it is impossible to create an app that lets you to autopost from Twitter/RSS/etc to Google+. But there is another way. And Google officially supports it.
I tested this method on my personal Google+ account and on a Google+ Page — it works well.
Google+ allows you to post via SMS. That’s the trick.
To autopost from Twitter to Google+ you have to create a Google Voice account. If you’re, like me not from the USA, you will need to use a US proxy for registration. Once registration is completed, you will not need a proxy.
Please note, that your Google Voice email address must be the same as your Google+ email account.
Google search: “how to get google voice outside of usa”
So, now you have a Google Voice account and US number. Go to Google Voice settings and make sure, that under the Voicemail & Text tab you enabled Text Forwarding to your email.

Now all the messages that you receive will forward to your Gmail.
Click on the red Text button and send something to 33669. You’ll receive an SMS that says “Google+: Did not understand the request”. That’s OK.

Open your Gmail and find an email with the same text in the body as above. Copy the From email address. It should look like
[email protected], where 1234567890 is your GVoice number, 33669 is the SMS address for Google+ and dPdcjkRaVz is your unique magic code.
This secret address allows you to post to your Google+ via email. But if you try to send something now, it won’t work, because your Google Voice number isn’t yet associated with your Google+ profile. To do this, open Google+ Settings and enter your number. Then verify it. Verification сode will come to your Google Voice number and forward to your Gmail inbox.
That’s it! You almost done. Now if you try to send something from your Gmail to your secret Google+ address, it will post on your Google+ stream. Note that email subject is always ignored, and you need to add +public at the end of the message (if you want to make it public). You can also share your posts only with a specific circle. Read more: http://support.google.com/mobile/bin/answer.py?hl=en&answer=1304920
The last step is to automate sending your tweets to that secret Google+ email address. I recommend to use ifttt.com. Just connect you Twitter account and create new task. For example, this is mine:
If new tweet by you then Send an email from Gmail.
In the To field enter your secret Google+ email address, in the Body field enter: {{Text}} +public
Click Create button. That’s all. Now all your tweets will be auto posted to your Google+ stream.