libiconv not linking to iOS project
As extra confirmation that the lib is included in your target, select the lib in the file list in the left pane of Xcode (assuming you've added it to your Target / Project, you should see the framework listed under frameworks), and show the Assistant Editor view on the right pane (View -> Assistant Editor -> Show Assistant Editor).
Then, with the relevant lib selected on the left, you will see 'Target Membership' for that lib shown as a list of checkboxes on the right.
You should see App Target Listed, and the checkbox should be checked for that target.
You could try unchecking and rechecking it, to nudge it into your project?