Instagram currently doesn’t allow users to share photos or videos from another website – you can only upload photos/videos directly from your mobile device. Since there is no sharing mechanism, there is no way for Social Warfare to include a button that will share your content on Instagram.
Should Instagram allow sharing from third-party sites in the future, we will definitely update Social Warfare to include an Instagram option. In the meantime, you can read about the social share button options we have for other sites here.