Zoji - As claimed by the developers of this Zoji, it caters online tools to aid you plan activities off-line.

EventBrite Online RSVP - EventBrite Online RSVP is a cost-effective event management software that provides services to help businesses organize, invite people together for an event, and sell tickets.

Evite - Send online invitations for all occasions by email or text message. Create invites for birthdays, baby showers, save the dates, or customize your own design.

Rsvpify Virtual Events - Rsvpify Virtual Events is an event management tool that provides you various functionalities ranging from setting up the entire event to selling the tickets online to the targeted audience.

PurpleTrail - Whether it is about birthday or wedding party or holidays, you just need to name the event and PurpleTrail will provide you the apt invitation solutions.

Whoozin.com - Free RSVP Online | Track RSVP’s and Sell Tickets for your events and recurring meetings.