Nightingale Legacy Portal
The trader list allows you to purchase remotely from every realm where you've already met a trader, but I've had a few instances where I was buying new furnishing recipes and didn't remember where I'd been. You don't get told you have to visit the trader first until after you try to make a purchase.
To make it easier to know which realms you can purchase from, traders you haven't visited (and their inventories) should be shown in red.
Sorry to double post.
How about:
A quest to tap all the three Gloom/Astrolabe/etc. Essence Traders?
I was writing what I'd missed on a post-it note, would be lovely to have Gloom Desert/Gloom Forest/Gloom Swamp just listed using the Quest interface each time. Maybe pick it up in the Site of Power, have the ghost of a Redcrosse Knight spawn after the final battle maybe? Or give it with the lore snippets?
Would be interesting to list unvisited traders on the Crude Portal screen, there is a lot of screen space that could be used.
Saves remembering which Traders you are missing - new players get frustrated if the penny doesn't drop on tapping every Essence Trader asap. They get in a low gear hardcore survival loop, make the game hard and can drop out before they experience the fun stuff.
Grey would be better than red.