BirdieSync application should automatically notify you when a new version is available. But note that even if a new version is available on BirdieSync web site, it may only be proposed gradually to current users. So it may be normal not to have received a notification yet of the new available version.
You may also register on BirdieSync forum: http://www.birdiesync.com/forum
Log in the forum.
Go in the News sub-forum.
At the bottom of the page, click on "Subscribe forum".
You will then get an email when a new topic is added in this sub-forum.
Caution: if you receive a notification by email, you won't receive a new one until you visit the sub-forum you subscribed to, being logged into your account.
To unsubscribe, repeat the same steps and click on "Unsubscribe forum".