Audience response systems have gained significant popularity since the start of the Covid-19 pandemic, although their history of usage is significantly longer than that. They are generally used to enable a lecturer to get feedback from his audience, perform knowledge assessments, or provide their audience with another channel for asking questions. In this paper, Audit, an audience response system implemented as a web application is described through its main functions, its architecture, and the implementation decisions. Audit strives to implement the main general functions of an audience response system including questions with multiple offered answers and questions with textual answers, but also to make them as simple and as flexible as possible and supplement them with rich additional features. Audit's flexibility is reflected in the fact that it supports ad-hoc usage without prior question preparation or audience or lecturer registration. Some of the system's rich features include textual answers with mathematics and special characters support, the ability for audience members to vote as registered users but still submit ananymous answers if necessary, and the option of automatically clustering aduience textual responses. Audit was after implementation evaluated in university lecture sessions with excellent results. Suggestions for improvement obtained in the evaluation are discussed in the paper. Audit is a free audience system available online at www.audit.altii.online.