I'm wondering if anyone has recommendations for an invoicing app that works well and doesn't require the receiver to also have the app. I need something that will allow me to create and send invoices, and keep track of what has been paid or not. Currently I use an archaic method of creating an invoice in word and then emailing it, and then marking it paid when I receive payment. I've heard good things about "Invoice Simple" but wanted to see if anyone had others they liked. Thanks!