It would be great to have the ability to create invoices for students such as sales or private instruction etc. and have the students log into the online portal to pay for their open invoices.
This could also be done for unsigned documents such as waivers or release forms as well.
You can add function to this that if there was an open invoice on someones account then after X amount of days it assigns a flow tag that send the student an email with a link to pay for their open invoice.
Imagine the possibilities..