Please provide a minimum detail of the theme in use. Otherwise normally peoples will give solutions taking that you are using default WP theme.
It fully depends on your theme’s functions.php
file how you will define it to appear through template file and CSS. The thumbnail generation is done by timthumb.php
. Most premium theme frameworks has this function by default. Only checking the box works. You can check WordPress.org theme repo for such free alternative and work on the graphical part.
Otherwise with default theme the work is a bit tedious.
timthumb is not part of WordPress. It isn’t needed. In my opinion commercial themes that do include it are anything but premium as the inclusion of timthumb indicates that the developer is doing it wrong.
See the post thumbnails page on the codex
http://codex.wordpress.org/Post_Thumbnails
Yes timthumb is not part of WordPress, rather its a separate project plus has vulnerabilities. cubecolour said it right for sure. WP post thumbnails does the most basic works needed, indeed.
I have iBlog Pro 4 theme I have to do?
you need to contact pagelines for support as support for commercial themes is not provided on this forum and is part of what you are paid for when you bought the theme.
ok. Why is a plugin for insert the info of a app store app?
ex: http://i43.tinypic.com/2j5bpl.png
Right.
They have a dedicated own forum too : http://www.pagelines.com/forum/