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.
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
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.
Invision - Prototyping and collaboration for design teams
Zoji - As claimed by the developers of this Zoji, it caters online tools to aid you plan activities off-line.
Sketch - Professional digital design for Mac.