You can always add on to your WeddingMix lite package. One add-on is the custom app code and auto-instagram.
Upgrade to custom app code and instagram import here by clicking on the green plus button on your account page on the website.
* We'll import everything tagged on instagram with your hashtag for 7 days before and after your wedding. Just make sure your friends have their profiles set to public for at least one day after the wedding.