The user interface looks very simple, easy-to use with drag & drop options of graphics or text boxes etc., which makes it really great! It's not only about creating invitations but also managing attendees' details like names/emails along side their contact numbers so as well can be added in mobile apps too (which I haven't tested yet). For any type of large scale functions such this one might have many participants who may need different types / kinds information at once time - then there would definitely multiple sections open up where they could fill out info individually if needed by them without affecting each other section i guess? But overall its quite good experience using blackbirds rsvp tool!! 1) Greatly helps us organize our invites2.) Easy way through we send bulk emails3.). Helps manage attendee data4.- Have option set reminders5..