Attorneys and court systems tout this website/app as being great for coparenting but as a user for three years, I would strongly suggest you find an alternative means of communication.
The app is not free on your phone, but the website(with serve limitation/ software bugs is), this was poorly explained to me during the mediation process, and had I know the limitations of the app, I would not accept that for my coparenting agreement.
The software/ application is poorly supported, buggy, rarely updated and inconsistent with how messages are sent, received, etc. You can send messages that do not get received by your other partner for several hours. Same goes for dates.
As this app is relatively new, and most coparenting agreements will span the adolescence of children. I highly doubt this app will exist for 18+ years without being purchased or absorbed by another company, leaving you at the mercy of whatever the developer chooses to do after they have extracted as much cash as possible from unsuspecting abs confused parents.
If the app works for your specific situation, great but for most situations is a cash grab from insiders of the divorce legal world, that don't have anything substantial to offer.