Tap on Performance Evaluation from profile page and then start the evaluation.

In this page, you can see 5 performance factor. 
SELECT USER, COMMUNICATION, ENTHUSIASM, PARTICIPATION, QUALITY OF WORK, DEPENDABILITY

1. Select User, you can add the user whom you want to evaluate
2. Communication, you can evaluate the user on the basis of communication
3. Enthusiasm, you can evaluate the user on the basis of Enthusiasm
4. Participation, you can evaluate the user on the basis of participation
5. Quality of work, you can evaluate the user on the basis of the quality of work
6. Dependability, you can evaluate the user on the basis of dependability
7. Your evaluation scale will be 1 to 10, and you can drag the slider accordingly

After Evaluate a user, tap on Submit, and then you can see the EVALUATION history.