I don't actually use this, but I found it recently...
I recently added the NoScript extension to my browser so I can shut down advertising-related tracking scripts.<p>As a result, now I see all kinds of interesting scrips that get loaded when I visit a site.<p>One day visiting CreditKarma.com I saw "Sentry.io" ... hmm that sounds interesting...<p>Turns out it's for monitoring applications. I don't use it, but thought I'd mention it, as I might investigate using it in an upcoming app.<p><a href="https://sentry.io/" rel="nofollow">https://sentry.io/</a>