Yes. With the new update of Unlock:OKR, you can applaud your peers for having achieved 100% of their target.
A clap icon can be seen on the KR listing page of your dashboard. It may also be seen on the people view page on the contributor hovercard. A default praise notification is sent to the achiever as you click on the clap icon.
After you have sent the praise, the clap turns yellow with animation. This indicates the message has been sent. Next time, if the person who has praised views the same KR, they will come to know that they have already given praise to that user.
Note: This praise can be sent only once by the sender to the receiver for a particular Key Result.