When trying to set up an Hourly alert on a free account it says "Please _register_ your account to ...". Apparently, it's a $10/mo feature, so you may want to reword the message to explain that and also link respective part of the price list from the message itself.

Also, "Purchase Upgrades" button is not clickable - https://i.imgur.com/uIyrIFv.gif

PS. I'm curious to see how well it works, but from what I saw so far - well done, break a leg. Saying this as a user of Talkwalker and F5Bot ;)