!! Imporant !!
When using the Free app do not "Empty the Cache" in your web browser.
Doing that will delete all of your Invoices and other data!
You can read the Userguide here.
Here are a few tips to help get you started...
1. The first thing you should do is fill out your "Preferences". These are used to setup and "fast-fill" your invoices
2. Next you should add some products and/or services you commonly offer. These too are used to fast-fill your invoices
3. You can add new clients and customers to the Contacts app when you create a "New Invoice". After that you can use the Contacts app to fast-filled your invoices for them.