Bookipi Invoice App - A minimal, beautiful invoice app for freelancers
Letterflix - Send letters and snail mail online to the USA, Europe, India, or anywhere in the world. Letterflix is the easiest and secure way to send letters and snail mail anywhere in the world from the comfort of your home.
Billdogg - Beautifully simple invoicing for freelancers
DocuPost - Sustainably mail letters, checks & postcards online from 75¢
Invoice.to - A simple & beautiful invoice generator with Stripe & Paypal
Letter to Yourself - Send a physical letter to your future self