It seems like you cannot search using Emoticons or Emojis.
For instance if I try to search on 
within the Sample Projects, it does not find anything. There are notes with this character in them.
Is this a bug, or intentional? Or perhaps I am doing something wrong.
At the moment these are indeed not indexed.
How to find open tasks from notes? Can it be searched (and saved as search)?
Did not found out how to do it (on iPad).
Not possible yet, but we have plans for this. Stay tuned!
+1 on being able to find notes with undone tasks
Is it possible to limit searches to a given category?
I’d like to save search views for all on the agenda across all projects in my “personal” category separately from my work one (and my community work one) - I tend to get a bit overwhelmed and distracted when I see them all at once 
Not possible yet, but we’ll take it on board. Improvements to search are in the roadmap.
Is it possible to search for due or overdue reminders within agenda? So I don’t have to use that ugly apple reminder interface?
Unfortunately not yet, you can search for reminders in general by typing #remind in the search field, but you can’t yet filter on due vs undue.
Is there anyway to search for all notes NOT assigned a date?
Not at the moment no, we’ll think about it.
I’m curious if there’s a way to search for an exact phrase. I’m trying to search for “build vm”, but it appears that the quotes don’t work like they do in e.g. google - I get the same results as if I’d just written the two words as separate terms. Is there a way to do this?
I’ve usually used plain text files for notes in the past, so not being able to drop into the shell and just grep through my notes for when I really need to find something specific is a little frustrating. More power added to searching would be a huge improvement here!
I’m curious if there’s a way to search for an exact phrase.
Alas, not yet, we hope to make this possible in a future update.
Is there any update on the search functionality? I’m seeing lots of old posts saying this is something high up in priority but nothing about timelines or updates being released. Search is probably one of the most lacking features and it’s extremely important to be able to find everything in an app that’s meant to collect lots of notes
We agree that it’s one of the most pressing areas, and we do aim to improve it significantly this year, but first have to get some other things out of the way first.
Is it possible to limit my search to a particular string and no more? My issue right now is that I’m trying to find notes that contain “pH”, but the results are useless because there are hundreds of them full of “phone”, “Phil”, etc, etc.
Not at the moment, we hope to offer more options the future.