I’m going to be in a situation that for a number of weeks throughout the next year my linked notes for PKM and projects needs to be iPad centric as that will be the only device available (I’m away from my office).
What is recommended that will allow easy linking in a decent UI? It would help if when I’m in the office I could pick it up on my mac.
Currently Devonthink is my main repository, but wiki links don’t work on DTTG.
If you trust iCloud, Obsidian works well. Just be sure your vault is in the Obsidian folder in your iCloud Drive.
Depending on how technical you are, Git with Working Copy may also be a good option for syncing your Obsidian vault.
Craft if you don’t want Markdown or local file system access. It’s gorgeous.
NotePlan is nearly identical in iPhone and Mac, and I believe the iPad app is there too, especially with a keyboard.
It’s a beautiful Mac-assed app, with customizable themes (and syntax!), and a variety of themes available. Templates can be used to customize notes, and even can pull data in from outside the app, and from the web.
It has a lot of plugins.
It not only has a great plug-in system, but they’re being actively developed and improved, as is the app.
It syncs quickly, and runs on plain text files and markdown.
Linking: it uses wiki links with autocomplete, can link to headings in another note, and has a synced lines function (similar to synced blocks in other apps, with some differences; but if you make a change in any synced line, the changes propagate to all its copies very quickly).
There is a URL scheme, so its easy to link in from outside the app – and even better, many (all?) of the plug-in actions can be invoked from the URL scheme – I have a Drafts actions I use to quickly add tasks, bullet points or other material to specific parts of my daily notes. You can even switch display templates using links in the app.
Drawbacks: no tables (unless you make them with tabs 
). Doesn’t include some markdown extensions, like definition lists. The text files that contain all your data live in a CloudKit folder, with a weird location on the Mac; so using the same notes with other apps (eg, Onsidian) is very doable, but the notes have to live in that location.
Opinions (as in, an opinionated app): Daily notes, tasks, calendar items and other kinds of notes are all roughly equally important.
I know there was a long thread about NotePlan recently, but there have been some good improvements and since then.
I may not understand what you are needing, but are you aware you can link Apple Mail, Notes, and Reminders to each other?
Just open Notes & Reminders side by side and drag from one to another. The same trick works with Mail and Reminders,
And yet … can you link one note to another?
If Apple ever makes that possible / easy / easily discoverable, the PKM world may feel the aftershocks.
Nope. AFAIK tagging is the only option.
Thanks all. looks like Obsidian is a strong contender
I’m going to only have an ipad available for a number of weeks in the year where I’m away for my office. I currently make a lot of notes that are linked to one another in Devonthink. DT wiki links don’t work on mobile, so I’m looking for an alternate solution.
I use craft for this exact use case
As a recent convert myself, I’ll just say I hope NotePlan continues to meet your needs! I’m in NotePlan quite a bit everyday. It meets my needs and actually has that something extra that makes me happy to use it. I owe my interest in this app to its enthusiastic users on this forum, as well as the many forum members who are willing to try anything new and shiny and report back. 
Why not Craft or Agenda?
Notes in v2 (when I last use Noteplan) didn’t link to the calendar notes. Has this been resolved? Can you link to any note anywhere? Is the notes function a first class citizen? I use omnifocus so the Reminders integration is of little importance to me.
I’d say 75% of the time I use Obsidian is on my iPad, but I also use it on a Mac and iPhone, all synced via iCloud. It has been working well for over a year now.
You can link any note to any other in any of several ways, and daily notes (and soon the new weekly notes!) have special linking options:
wiki-linking: just link to a [[project note]] by title, even if it’s in a sub folder, or by date [[2022-07-15]] for daily notes;
modified wiki linking to [[a particular note#heading]] or to [[a particular note^synced_line]] (going from memory on that last one – I don’t use it)
full url linking to notes in the repository: [link text](noteplan://x-callback-url/, which can open notes, add to or create notes, invoke commands (like adding to specific headings, changing themes, inserting templates, etc) and more
full url linking to documents or apps outside NotePlan: [link text](app_url_scheme://path/pr/command)
link a particular line/item (task, bullet) to a date:
- Repeat until conpleted link to >today
- Linked to specific date >2022-07-16
Link a non-task or bullet to >2022-07-16
(That last one shows up as a bullet in the daily note, weirdly – will alert the dev.)
Anyway, @svsmailus, if you haven’t tried it since v2, check it out – it may well still not be for you, but at least then you’ll be up to speed on why not.
Edit: I think the forum software modified some of the example markdown syntax. The first item should use a hyphen, which I have set to be a task, and the second an asterisk, which I have set to be a bullet
