Originally Revealed in Kickstarter in October 2015, Spirit Island Funded quickly and surpassed goals, reaching a total of $84k. It was released in July 2017, and sold out quickly. There have been multiple printings since then.
The first Expansion adds a lot to Spirit Island, including additional Scenarios, new Tokens with unique effects, and Events, along with additional Spirits and Adversaries. It was composed of multiple Stretch Goals in the original Kickstarter, a $60K goal for additional Spirits Effects (the tokens) and Events, and another $80K goal adding the two additional spirits, both of whom make use of the new tokens.
The Promo Spirits were two additional Promotional Spirits released during the Kickstarter, for the $40k Stretch Goal and the $70k Stretch Goal. They were available for a limited time after the release of the game as well, in a special Promotional Pack, and are occasionally reprinted, but are not sold through normal distribution channels.