One of the best encrypted messaging apps available appears to be working on the ability to add or edit a contact without leaving the app, which WhatsApp for iPhone has supported for some time.
The contact can be saved on either the phone’s storage or the user’s paired Google account. You can also make changes to previously saved contacts, such as adding inputs to new fields like birthdays or email addresses, directly on WhatsApp. This may appear to be fairly basic functionality for an instant messaging application, but it is far superior to not having such a feature.