解答：
After Xcode 7, Apple did a lot to strip the size of apps, including changing .dylib to .tbd.
Here you don't need to add library & framework but you can add the library by changing the following option:
Other Linker Flags > Add "-l{yourlibraryname} (no space after -l)
In your case, you can add -liconv in Other Linker Flags.
xcode7: Undefined symbols for architecture i386: "_iconv_open", referenced from:
