If you haven't already created a Helipad account, register for free at helipadapp.com.
Launch the Helipad application, and click on the preferences icon:
Enter your Helipad username and password in the preference pane:
Click on the "Sync" icon in the toolbar to sync your documents.
Working offline is easy! Once you have successfully synchronised your documents, you can edit them without requiring an Internet connection. Once you're back online, click the sync icon to send changes back to Helipad.
Your changes will then be saved to the Helipad web application.