Source: http://lifehacker.com/#!5789383/add-custom-webapps-to-chromes-new-tab-page
While custom new tab pages like previously mentioned Myfav.es are great, some of you may prefer Chrome's default for its easy access to Chrome-only webapps. Here's how to add your other favorite pages to Chrome's new tab page.
By default, there doesn't seem to be an easy way to just add any old web site to Chrome's new tab page. If you want just as quick access to, say, Lifehacker as you do the New York Times or TweetDeck, reader andrew.yeh.10 shows us how:
You can create webapps for the Chrome new tab page even if they're not in the Chrome Web Store.
Make a new folder and create a new text file called "manifest.json" inside it. Fill in the name, description, urls, and launch page:
{ "name": "Name_of_web_app", "description": "Description of web app", "version": "1.0", "icons": { "128": "128.png" }, "app": { "urls": [ "http://yourwebsitehere.com" ], "launch": { "web_url": "http://yourwebsitehere.com" } }, "permissions": [ "unlimitedStorage", "notifications" ] }
Then, in the same folder, save a 128x128 png image as "128.png." This will be used as the webapp's icon.
After this is done, go to chrome://extensions/. Open up the developer mode (top right) and "Load unpacked extension." Navigate to the folder you created and hit OK.
Alternatively, you can "Pack extension" by clicking the option and navigating to the folder. This will create an installable .crx file.
Dropbox can keep your personal chrome web apps in sync between computers.