Contactulater app for iPhone and iPad

With Contactulater youre always in control who of your contacts has which of your contact details. At the same time it ensures that they are always up to date, no matter whether you moved, got a new phone number or anything else changed. The same way they ensure that your contact book is always current without you having to do anything for it.
As a bonus all your data isnt saved anywhere centrally but only on your devices and with the contacts you shared with. And of course all data transfer is end-to-end encrypted.