Riku is a free and open-source software that lets you collect responses from forms on your site. Forms to:
Point your forms to Riku:
<form action="https://riku.miso.town/submit?user_id=1" method="post"> ... </form>
...and retrieve all the responses on the web interface or via the atom feed.
Questions? Send me an email at m15o at posteo dot net.
Read the manual to learn more