Features

SwiftoDo offers the following features:

Todo.txt format compliance

Full support for the todo.txt format
Support for due date tags, as in due:2021-12-31
Support for threshold date (start date) tags, as in t:2021-12-01
Support for hidden task tags, as in h:1, which can be used to hide tasks that only contain task list metadata
Support for recurring tasks with the rec: tag
Archive completed tasks to a done.txt file (not necessarily with that name)

Sync with any file you can read and write via the iOS Files app (Files app-based sync is compatible with many file sync providers)
Dropbox sync

Syntax highlighting
Numerous sort options
Numerous filter options
Full-text search
Tap a task to edit it
Select multiple tasks and perform some edits on all of them at once (this is useful for things like changing priority or marking tasks complete)
Automatically adds creation date to new tasks (optional)
Retain priority after tasks are marked complete (as is, as tag, or do not)
Hide hidden tasks (optional)
Hide future tasks, based on threshold date tags (optional)
Assign a default priority to all new tasks (optional)

Syntax highlighting
Priority picker
Project picker, populated from your task list
Context picker, populated from your task list
Due date picker (either a calendar or spinner, depending on your iOS version)
Threshold date picker (either a calendar or spinner, depending on your iOS version)
Recurrence pattern picker (based on the recurrence pattern syntax)
Add multiple tasks to the task list at once (optional)