Each permission that the app uses is required by Android in order to implement specific features. Here is a list of how the permissions are used:
Location: This is needed to support location-based reminders for tasks, as well as the task map feature, in which your tasks are displayed on a map along with your current location. The coordinates of your device are never shared or transmitted by the app.
Read Contact Data: This is needed for the contacts feature, which allows you to link your tasks with contacts on your device. This feature is typically used for tasks that involve calling or e-mailing someone, or navigating to a location listed in your contacts. Contact details (name, e-mail, etc) are never shared or transmitted by the app.
Read and Write Calendar Events: This is needed for the calendar integration feature, which allows you to show your tasks on your device's calendar.
Network Communication: This is used for synchronizing your tasks and notes with a Toodledo or Google account.
Accounts: This allows you to synchronize your tasks with a Google account you have set up on your device.
Record Audio: This is needed for voice mode, which allows you to create and update tasks by voice.
Billing: This is required in order to implement in-app billing. An in-app purchase unlocks the app for use beyond the free trial period.
Phone Calls: While the app does not actually place or handle phone calls, it does use information from the phone to uniquely identify the device. This is used for enforcing the free trial as well as for customer support if necessary. Note that the phone number is never shared or transmitted.
Hardware Controls / Vibrator: Allows the app to operate the vibrator when a reminder occurs.
System Tools / Start at Boot: The app needs to run briefly after your device boots up in order to set up reminders for your tasks. Without this, your reminders would not appear after a restart.