Huh, interesting - why is it an extension, so the user is crawling themselves instead of you running a server? That seems like an odd technical decision.
But more to the topic of this as a product, how did you choose to do this? I’ve seen website checkers with similar featuresets for a long time, so it’s nice that there’s a market - how will you reach that market?
By doing the crawling locally, it means you can check as many sites as you want as often as you want including localhost sites. This is especially useful during active development as you can perform checks locally and on staging sites instead of only checking production sites when issues have went live. A cloud-based implementation would have to come with limitations on how often you can perform crawls and can be expensive to run.
I’ve mostly been reaching out to web developers on forums and online communities so far. I’ve had a lot of positive feedback about the interface and how Checkbot is finding issues missed by other tools.