Features added to existing website (PHP / MySQL / Javascript / etc)

I need to add 3 additional features to my website
1. an IP check feature - a button on a user\'s profile page, that when clicked by an online user, opens a window that shows this user\'s last login IP details, or if this user is online, show me his current login IP details. These info already exists in the main MySQL database, but might need to be modified to get the required results.

2. A add us to your desktop feature - a button in the header section to add my website to a user\'s desktop

3. An add us to your favorites feature - a button in the header section next to the above that add my site to someones browser\'s favorites

These features should follow the existing design and coding and not interfere negatively with the normal working of the site