You can now post to all FB groups in just on click for this purpose you have to follow these steps:

1) Login into your gmail account.

2) Compose a new mail & add the address of all FB (facebook) groups you want to post.

3) Type subject & at message type your status & click on send message

4) You will successfully post to all groups you want in just on click.

5) Please Share & buzz that post (Thanks).