From version 2.2 you are able to Edit deal details in mobile apps. To use and access this option click on “+” icon on the right side of the deal and select option Edit deal from the list:
​

The screen with deal details will load and appear, where you can make desired changes. Once done just press “Save” in top right corner to apply those changes.
​
​
Important note: Contact information are not editable. You are able to use trash can icon to remove contact completely from the deal (the client won't be deleted from your contacts list, it will be removed only from your deal) and use Add contact icon in header to replace removed contact with another one or simply, use this option to add more contacts to the deal.