When comparing aCalendar vs Todo.txt, the Slant community recommends Todo.txt for most people. In the question“What are the best to-do list apps for Android?” Todo.txt is ranked 5th while aCalendar is ranked 24th. The most important reason people chose Todo.txt is:
Todo.txt can be edited in plain text and then displayed with neat styles.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Good Tasks integration
Tasks get shown in the calendar, although there is also a separate tasks view. It supports Google Tasks and recurring tasks.
Pro Very convenient user interaction
Switching from day<->week<->month views by swiping laterally is a powerful feature.
Pro Lots of customization options
The settings menu is rather detailed and includes a good selection of color themes to choose from, possibility to adjust font-size, set beginning and end of day, ability to choose what views to use and more.
Pro Free, ad-less version available
aCalendar is an Android app that comes in free, ad-less version as well as this paid version.
This paid version aCalendar+ adds more features like agenda view, home screen widget and the ability to manage Google Calendars. The developer also donates some of the profits from this Pro version to help protect the endangered mountain tapir.
Pro Nice presentation
The three views are very convenient, particularly the week view, which shows the week position inside the month
Pro Good fullscreen widgets for all views
The app has widgets for day, week and month views.
Pro Color-coding support
The app has 48 calendar and 12 event colors.
Pro Can add public holidays to calendar from over 35 countries
For the 30+ available languages for the app, there are holiday calendars available to be added.
Pro Lunar calendar support
aCalendar can be set up to use a calendar based on cycles of the lunar phases.
Pro Unique Week overview
Its week overview is very well suiting for tasks and all day events. It shows everything at once.
Pro Drag'n'Drop
Drag'n'drop functionality is available in day view with this paid version of the application.
Pro Useful 3-finger tap to go to today
By utilizing a three finger tap shortcut users can easily got to the today view from anywhere in the app.
Pro Available in 30 languages
There are 3o user made translations available for the app, making for a good calendar to use in different countries.
Pro QR and NFC barcode sharing of events
Using both QR codes as well as NFC, users can share events wirelessly and easily
Pro Easily editable format
Todo.txt can be edited in plain text and then displayed with neat styles.
Pro Editable from any text editor without needing any proprietary software
Because todo.txt is just a todo standard with various compatible apps to edit it, you can update it from any device as long as it can edit text and you can access your todo.txt file
It's convenient to be able to access your todo list quickly via your programming environment so you don't have to switch contexts, and to have a separate todo.txt file per project.
Pro Works with lots of apps for every platform
Todo.txt lists can be edited in virtually every text editor ever made and accessed on devices that support Dropbox. The user community has also created a number of apps for dozens of platforms.
Pro Command line support
You can edit your lists using the command line (e.g., Terminal) via a supplied bash script.
Pro Full control over your to-dos
You have full access to the underlying programming rules, and therefore total control over your task lists.
Pro Extensible
Has been extended to include most things people want, including a multiple of interfaces and app for all platforms.
Pro Easy syncing
Todo.txt automatically and seamlessly syncs through Dropbox.
Pro Wide range of interface apps
The community has developed a wide range of apps that interface with the basic file structure. These apps vary in how much they accomplish, how much hand-holding they do, their level of glitz, etc. They range from plugins for an editing app like vim to stand-alone, platform-specific GUI's. So YMMV depending on what you use. (todopy is particularly nice, a Python program that has a "console" mode which provides a keyboard-driven GUI.)
Pro Follows the unix philosophy
Does one thing: to do lists
Pro It's free
It runs on MacOS, Android, and Python (in the Mac's Unix CLI) -- all for free.
Pro Easy to sync up between lots of devices and interfaces
At a bare minimum you just need to be able to edit text, but there are many apps and advanced interfaces you can install on many devices to supplement your to-do list editing.
Cons
Con Free version is very limiting
Free version of the application does not include common things like the agenda view, actionable notifications or attendee management among many other more advanced features.
Con Somewhat overwhelming amount of options
Con No support for reoccurring tasks
Tasks have dates corresponding to creation and completion, but there is no explicit support for due dates or for tasks that reoccur.
Con Nested tasks not supported
Many todo tasks for developers end up having sub tasks that need to be performed for a parent task to be completed, but the todo.txt format does not have any nesting.
Con Android app not updated since 2013
The app only seems to support Dropbox. It would be nice to see support for different and newer file storage services.
