You have asked for the anonymous feedback tool. First and foremost, taking feedback from employees is a good idea. This is not just a tool for upward communication, but it will help you gain insight into the psychology of the employees. A large number of organizations have grown because they conducted an "Employee Satisfaction Survey." Taking a clue from these surveys, they further brought changes in their working style or the organization's culture.
The Need for Anonymity
Coming to your query now. You have asked for a tool for anonymous feedback. The fact that you prefer a cloak of anonymity for taking feedback from employees speaks volumes about the flaw in your organization's culture.
If dissent is dismissed as disobedience or if dissent is suppressed, it does not get diluted but gets buried deeply, and the organization needs anonymity to unearth it. Therefore, as an HR professional, your first question is why your organization requires anonymity. What can you do to bring a culture of openness? Is the top boss wary of divergent views? What can be done for the free movement of upward information? Do you have means to capture information from the lowest level of the hierarchy, or do top bosses get feedback from their immediate subordinates, and are they happy with it? Is there a disconnect between managers and non-managers? Is there a disconnect between managers and top management?
As an HR professional, you might know the replies to the questions that I have raised. Nevertheless, if, due to your disempowerment or disentitlement to express your views, you prefer anonymous feedback from employees and bring to the fore that open secret, then there is nothing wrong; go ahead with the tool! The outcome of the survey will lend credibility to what you knew all along!
Thanks,
Dinesh Divekar