The biggest thing I need out of a mobile app is the ability to quickly add new entries.
I can sort them out later on desktop/web, but the biggest reason I still use Apple's iOS Reminders app is that I can put a button in my Control Center and drop new entries into an "inbox" from anywhere, in just a swipe and a tap.
Recently I've found that I can use iOS Shortcuts to create my own "quick add" function for certain apps that don't natively have it. In the case of Obsidian, I can directly edit the markdown file to append a bullet, but I don't know if that's a great idea for Legend (and I don't think the files are exposed to the user in iOS, either).
The other major way to accomplish this is with app URL schemes, which I have just learned about.
For example, I can create this link pretty much anywhere: shortcuts://run-shortcut?name=Your%20Shortcut%20Name
...and when I click on it, "Your Shortcut Name" will run via the iOS Shortcuts app. This works for non-Apple apps, too...but I gather the developers have to make it possible.
If Legend had an app URL scheme, I could make my own "quick add button" and be very, very, very happy.
By chance, does Legend already have one?
If not, how big a deal would it be to add?