To be really honest; the best App for that is
OmniFocus. It's a professional project management tool.
AppStore Link: OmniFocus - The Omni Group
Great review of OmniFocus for iPhone:
OmniFocus 2 for iPhone: Background Sync and a Bold Redesign - MacStories
OmniFocus is a lightweight, but extremely powerful app and I really tried every damn app and system on the whole App Store on iPhone and Mac and there is really nothing which is nearly comparable with it. BUT it might be a little bit complex at first sight, but trust me, it's freaking awesome! An on the Website of OmniGroup you have all kind of introduction and help. It's also one of the best companies. I had a lot of suggestions and belief me or not, you receive an answer always and directly within 48 hours and they also implemented almost every suggestion I had!
The Description on the website:
Here are some screenshots, the 4 screenshots are: Home view, Forecast view, New Entry (compose), Note view (within a entry):
View attachment 52488
It has everything you asked for, you can:
- quickly add actions (optional with notes)
- assign start dates
- assign due dates
- attach pictures and audios
- assign contexts (like places, people, devices etc.)
- organize your entries in groups, folders and projects
- create your own views with chosen projects and/or contexts
Furthermore you can see all your actions and notes in a "Forecast view" with today and the next days.
The calendar is also integrated, so you can see your tasks/notes with dates and your calendar entries.
Now to the quick capture; there are million ways to enter entries to OmniFocus. OmniFocus has a feature which allows it to capture entries which are in the stock Reminder app and import them in OmniFocus entries and also get there due dates, notes etc. That's why you can use everything which is for the Reminder app also for OmniFocus.
Here a some examples how you can add entries (and how I do daily):
- Drafts: Send a action or note from Drafts app to Reminder, you can create a list of things and send them all to Reminder, you can send a note directly to OmniFocus to modify it in OmniFocus, you can send a list of stuff to OmniFocus (will be send to Reminder and directly opens OmniFocus to import them)
- Reminder: You can also just use the Reminders app to enter stuff which will be captures and transferred to OmniFocus
- OmniFocus Widget: There is a awesome OmniFocus widget which displays your entries in your Todays view in Notification Center (which is absolutely great!!!) and you can also tap on the entries which opens the app and directly to the taped entry. You can also directly use the compose feature and create entries with the widget (see screen shots). Additionally you can install CCLoader which allows you to set and arrange widgets in the Control Center, so you can place the widget also in the Control Center if you want to.
- Siri: you can use Siri to create entry in Reminder app which gets directly to OmniFocus. I mostly use this when I'm doing sport (running etc.) then it's awesome to launch Siri and just say stuff which is saved without typing anything.
- ProWidgets: I think the easiest and quickest way is with the Reminders compose widget from ProWidgets, so you can invoke the compose windows to create entries (see screenshot)
- Action Menu: With the Action Menu Addon "ActivityAction" you can perform a action with a selected text, like google the word/text, send it to other apps like Google Maps, dictionaries or to OmniFocus (in this case). (See Screen shot)
- Every URL scheme handling app & tweak: with the URL scheme for adding new entries in OmniFocus you can use it with a bunch of tweaks in Cydia and Apps in AppStore, like LauchCenter Pro etc.
Here are the screen shots of the mentioned ways to input stuff: