I don't know about Instagram (haven't used that much), but I'm shooting for (long-term) a card-based, simplified replacement for tools like Confluence, which I find overwrought and difficult to use.

It uses cards, so I suppose it superficially resembles Trello and similar agile board-esque tools, but it definitely has a different feel to it.

I actually got the idea for the basic layout from Pintrest (I originally had a masonry-like layout to the cards, but switched to CSS grid -- makes sorting/searching/scanning for something specific easier, IMO).