If Twitter post then Google+ post
I tried the Facebook Applet shared by someone else but it appears to be broken. This Twitter Applet I cooked up is tested and works great! You'll need to set up your Google+ account to be able to send posts from SMS via Google Voice. Your Google+ account and Google Voice account need to be using the same email address I believe. 1. In your Google Voice settings on the Voicemail & Text tab, turn on text forwarding to email. 2. Save changes and send a new text via Google Voice to 33669 (Google's SMS number). An SMS will come to your inbox with an error. Check your Gmail account and you'll find the same error in an email. 3. Copy the from email address which will include your GV number, Google's SMS number, and a code and end with @txt.voice.google.com. 4. Add your Google Voice number to your Google+ profile in your settings. Follow the verification process to add the number. 5. Paste the long email address you copied earlier into this Applet as the "to" email and make sure your Twitter and Gmail accounts are authorized for IFTTT. Anything you post to Twitter will be scraped by IFTTT and sent through Gmail to your personal Google Voice email address which posts to Google+ via SMS.