updown.io

updown.io is an uptime monitoring service from France. It checks whether your sites respond and alerts you when they do not, and the pricing follows just two variables: how many sites you watch and how often each one is checked.

The service runs in the EU on Hetzner, which makes it a European alternative to the American monitoring platforms. The simple, low cost model suits small teams and individuals who look after a handful of sites and do not need a full enterprise monitoring suite.