All the icons used in the app are defined dynamically and can be customized.
Icons.shared().block = new IconicsDrawable(context, FontAwesome.Icon.faw_user);
This will change the block icon to be the FontAwesome user image.
You can reference IconicsAndroid for more details.
Here is a full list of the icons that can be customized:
public IconicsDrawable dummy;public IconicsDrawable location;public IconicsDrawable user;public IconicsDrawable phone;public IconicsDrawable email;public IconicsDrawable chat;public IconicsDrawable check;public IconicsDrawable save;public IconicsDrawable block;public IconicsDrawable publicChat;public IconicsDrawable contact;public IconicsDrawable edit;public IconicsDrawable logout;public IconicsDrawable search;public IconicsDrawable users;public IconicsDrawable copy;public IconicsDrawable delete;public IconicsDrawable forward;public IconicsDrawable reply;public Drawable add;public IconicsDrawable microphone;public IconicsDrawable cancel;public IconicsDrawable play;public IconicsDrawable pause;public Drawable send;