You can synchronize your hiTask with calendar apps on your desktop or mobile device.

HiTask is providing your calendar feed using industry-standard CalDav protocol. Among applications that support this protocol are Apple Calendar, iOS Calendar (iPhone, iPad, iPod touch),  Mozilla Thunderbird. MS Outlook does not support this directly but it may be possible using third party add-ons.

To Connect to hiTask calendar user this address: secure.hitask.com/calendar/<username> where <username> is your hiTask account user name. For example if your user name that you use to log in to HiTask is john, calendar address will be secure.hitask.com/calendar/john

You also required to enter your hiTask user name and password.

Instructions for Mac OSX Calendar

Instructions for iOS Calendar (iPhone, iPad)

You can upload files to your hiTask account just by e-mailing them! Sometimes it's more convenient to forward files by email rather than uploading them.
Your email will be converted to a task or a file depending if there's any text in the email.
When you send an email without any text in it, the file will be created in your account. If you send an email with text and an attachment, it will be converted to a task with a file attachment, or attachments if there's more than one file.