Good afternoon sisak1973.
I see how convenient it could be to have messages auto forwarded if your phone is off. We offer this feature for phone calls, (Call Forward/ No Answer Transfer); however, it is not available for text messages. I haven't heard of an application being available for this either. However, we do have a feature called VText , which you can use to send/ receive messages from our website. Please view the link for information and options to set this up.