This extension will always be free and will never have ads.
Once installed, a home button will appear at the top right of Chrome that initially redirects your current tab to the list of your most used sites. Right-click the button and choose Options to edit the home-page url, the icon, and the new-tab behaviour.
You can hide the official home button at top left via: Chrome Settings > Show home button > Disabled.
This extension only uses the tabs permission, so when you install, it will say that the extension can: "Read your browsing history". This extension never monitors your activity. It only redirects your tabs when requested. The source code is very simple and is posted online, so you can inspect it for yourself.
In response to Chrome's Feb 2014 removal of the flag that let you default your new tab to the Apps view, I've added a checkbox that lets you default the new tab to the Apps view.
In Dec 2019 the new-tab-to-apps stopped working, so I updated the extension with a fix. At that time I also added Federico's code to support multiple urls. And I acted on Darren's suggestion to make the default url "about:newtab", and to offer a white button for the dark theme.