How often does the feed update, and how many posts can it show?

Fetched posts are stored in a cache file for a duration you set (one hour by default), and the module fetches fresh data from Instagram when that cache expires. A back office refresh action lets you clear the cache and pull new posts immediately when you have just posted something you want shown right away. Each fetch requests up to 25 recent posts from Instagram, so the storefront count you choose is capped at that limit.