Nightbell

Point Nightbell at anything that answers over HTTP, or at one element on a
rendered web page, and it watches it, charts it, and gets loud when it
breaks.

There is no server and no account. The phone in your pocket does the
checking, and your API tokens and target URLs never leave the device.

Three kinds of monitor:
- Status check: hit a URL, assert on the status code.
- Request and response: pick the method, set headers and a body, assert
on what comes back (contains, equals, regex, or a JSON field by path).
- Page element: load the real page in an embedded browser and watch DOM
nodes you picked by tapping them.

Urgent alerts arrive as a full-screen red page with a looping alarm that
keeps going until you acknowledge it, and it wakes the screen even if the
phone is locked. A first-launch screen walks through the four Android
grants a paging app actually needs (notifications, unrestricted battery,
full-screen intent, Do Not Disturb access), because two of them have no
system dialog and have to be opened by hand.

A home-screen widget shows the worst monitor first. Settings let you shape
the alert policy: what counts as down, sound, haptics, escalation, and
quiet hours.

Signed with the developer's own key. No Play Store listing.