Letter Carrier - Certified Mail, First Class Mail, STAY AT-HOME POSTAL SERVICE. WE PRINT, FOLD, AND MAIL QUICKLY! The Letter Carrier app allows you from any location to send certified mail and first class mail without having to visit a post office — no more unnecessary trips to the post office, or buying stamps online, no more printing and affixing shipping labels, no more envelopes or shipping supplies needed, and in 3 easy steps we do all the work and mail for you. NO need to buy print paper, NO need to print a document, NO need to buy... read full review »