Admin Options Pages is a beautifully designed WordPress plugin, which makes it (incredibly) easy to create options pages, fields and menus.
If you'r a seasoned developer or just a beginner, Admin Options Pages tries to make it easy for everybody.
Behind the scenes AOP makes use of a variety of WordPress functions and APIs. Menus are using the add_menu_page function and the Settings and Options APIs are used for creating the pages and the options fields.
I.a. Checkboxes, radio buttons, textfields, textareas, images, colorpickers, numbers, titles, descriptions, horizontal rules. The list with options fields is still growing.
There are option fields which gives you the possibility to overide some default functionalities. For example by using the add_filter function to handle your own validation callback.
With AOP you can save a huge amount of time and money. And yes its free.