obfuscatr is the email address obfuscator. Its purpose is to obfuscate the email address in a way it couldn't be reached by the bots crawling the web for emails.
By the latest studies over 97% of the spam is sent to addresses that have been posted on public websites. Such addresses are naked.
'Naked email' stands for an email that is readable to various bots, including Googlebot. So email harvesting bots, that grab the email for a spammer, don't even have to reach the site the email resides but rather get it from Google.
A lot of people prevent that by posting their email addresses like me [at] mydomain.com or just replace the @ sign with a graphic. Does it help? Well, if it's a bot, automated tool relying on programming, would it be that hard to modify its search criteria to also match the addresses formatted as me [at] mydomain.com? Please also note that spamming has a fully commercial background these days.
To use obfuscatr just paste or type in your email, click 'Obfuscate!' and it will generate you a code that you can use on a web without exposing the email. To a visitor it will look proper. To a bot — not really.