Freshping is good and has all I need to check both my internal sites, servers and clients website.
I would like to suggest a feature for http/https check. Suggest to add a check for text for a site. This feature will check a text on a particular site and this would allow site owners or devteam to check if their website has been defaced/hacked.
This is also a form of web checking. and it will be a useful feature for everyone.