I love that you can add people to a calendar event and it updates them right away. You can also put more then one reminder and colour-code all events. This is an excellent app for me to use with my boyfriend so that we never double book or forget about each others plans! I have not had any issues, but do the updates! If you dont do the updates, the events added by someone else to your calendar wont always show in the app on your phone!!
Emmusky65;6776 about TimeTree: Shared Calendar, v2.0.0