It’s not fair to have favourites, but Unfold is certainly top 3. It’s a super user-friendly app for creating stand out Instagram Stories. It offers up to 100 chic and minimal templates (it’s free, but many of the templates involve an in-app purchase of around £1.99 per series). I’ve recorded a short tour that will give you an idea of how to use it.
My phone has space for more, so I’d love to hear your recommendations.