Tap on the "Profile" tab, then tap the gear icon to view the "Settings" screen.
Under the "Push Notifications" heading you can individually toggle each type of push notification between ON and OFF.
You may encounter a message that reads:
"Notifications are currently disabled. To enable them, go to Settings on your iPhone and enable Notifications for Klout."
In this case, head over to your Notifications center, click on the Klout app and make sure that "Notification Center" is set to "On" and that "Badge App Icon" is also set to "On." When you return to the Klout app and visit your settings, you should now be able to flip those switches.