Klout, the social influence measure that is likely the most used and well-respected, rolled out a series of changes yesterday. They upgraded their iPhone app to include more features and made changes to their +K system.

Giving someone a “+K” is like voting for them as an influencer for a particular topic. This helps their Klout score, which ranges from 10-100, and highlights them within that particular topic. Until today, an individual could be influential in up to 20 topics, but Klout expanded it to include all of the topics in which a person holds influence based upon their social media activity and recommendations of others. This feature seems to be working intermittently and may just be a glitch.

They also rolled out a “Why” component that gives users 140 characters to explain why they’re giving Klout to a person. Similar to a review, it adds more depth to the voting process and likely holds more weight when a user includes a reason rather than just clicking the +K button.