Doesn't work with MIUI ROM - they block third party apps of this type.
• download additional themes from Google Play,
• connect with facebook, and download full-screen photos automatically(and browse albums!),
• customize caller ID screen content,
• switch between caller screen Themes, choose 'click' or 'slider' behavior of buttons,
• choose full screen caller ID for all or only a few contacts,
• full screen caller for incoming calls,
• full screen caller for outgoing calls.
1) go to Themes,
2) select and edit,
3) move buttons by holding and dragging,
4) switch to slider with a single click on a button
(FIRST you need to drag a button to the edge of the screen)
5) change default contact photo from the MENU button,
6) switch to other states of a call by swiping left or right,
7) reset to default from the MENU button