Q: Regarding your article about to-do lists, what are the best apps for handling work tasks and other reminders on an iPhone?

V.L., Ellicott City, Md.

A: The answer depends partly on your personal preferences. Several widely used iPhone apps go beyond basic list-making, sync with other devices and applications, and work with widely used time-management systems, such as David Allen's "Getting Things Done" or FranklinCovey's "Focus." Pocket Informant, by Web Information Solutions, allows users to group and filter tasks based on their context, status and urgency; assign icons to events or tasks; organize tasks into subtasks; and add photos and contact information. Available at webis.net for $12.99, the app also includes calendar, notes and contacts functions. An app called 2Do, by Guided Ways Technologies at 2doapp.com, enables users to drag and drop tasks to and from a calendar and toggle between task lists and projects or goals. It also syncs across multiple devices and applications and is available on iTunes for $6.99.

Toodledo, available on iTunes for $1.99, enables users to track tasks' priority and deadlines, sort them by context or subject, set reminders, add notes and filter the most important items into a "hotlist." Remember the Milk is a widely used to-do manager that offers an iPhone app free on iTunes, allowing users to sort and prioritize tasks, set locations and reminders and store notes on each item. And Evernote, also available free on iTunes, enables users to attach notes, ideas, photos and recordings to multiple lists or notebooks.

Write to Sue Shellenbarger at sue.shellenbarger@wsj.com