Apps used to appear on a new tab now they are accessible anytime from your bookmarks bar. Look for an icon similar to this in the left corner of your browser.
or like this:
Google Apps has an all-new look across all its core apps that helps you work more quickly and focus on what's important. Most changes are cosmetic and don't really need any explanation. But some differences are worth noting.
Here is new icons you will see - note the black bar isn't always present anymore instead you might be seeing something like this: