I have recently started using Obsidian for note-taking. I like it, but there are currently no Mobile apps and no quick way to capture notes into the application from your iPhone or iPad.
Luckily, it's pretty simple to add notes to Obsidian from outside the application because Obsidian basically just reads and writes to a local folder on your mac. So, if you place your Obsidian vault inside iCloud Drive or Dropbox you can basically read and write to the notes from anywhere.
So, I made an iOS Shortcut for this purpose! I know that CGP Grey use the 5$ app 1Writer to access his Obsidian files from his iPhone and iPad - he describes his workflow here (approx 45 minutes in). However, if you are not looking to change your files, but for a way to only add quick thoughts the Obsidian, this shortcut is the faster, cleaner and free option. You can follow these steps and download my Shortcut to start quick capturing into Obsidian from your iPhone:
1. Place Obsidian Vault in iCloud Drive (or Dropbox)
First, place your Obsidian vault folder inside iCloud Shortcuts folder or other folder that you sync across devices. If you use iCloud for syncing, Shortcuts can currently only export files to the Shortcuts folder, so the vault needs to be located there. I suspect you can use any folder with Dropbox.
2. Use This Shortcut to Save Markdown Files to Obsidian Vault
Go to Shortcuts on your iPhone. You can build a shortcut yourself or download mine here. My shortcut simply prompts you to write a note and then saves your note as a normal text file into your iCloud Drive. Finally it changes the extension of this file to Markdown format (.md) and deletes the original text file.
This shortcut titles the note with a time stamp. This has the advantage of saving you time when capturing (you can change the title later in Obsidian) and avoiding name conflicts that could lead to error in Shortcuts.
3. Place the Obsidian Shortcut on Your Home Screen
That's basically it. You can place the Shortcut in a widget on the iPhone or iPad home screen for easy access like me. I am astonished of how fast it synchronizes - when you capture a note it will show up in Obsidian in seconds.
Update: After posting the shortcut on r/ObsidianMD, a Reddit user confirmed that it works with Dropbox. The user also had a great idea about directing all the iPhone/iPad notes into a folder in Obsidian for later review:
Credits: My shortcut is an adaptation of this shortcut for changing file names via Shortcuts.