Android can warn you when approaching your monthly usage limit...but what if a rogue app consumes all that data in the first two days of the month?

Detect spikes early with a custom alarm - pick your own "normal" usage and time window (ex. 30MB in 30 min, 100MB in 24hr), and an "always on" monitor will keep guard for you. No ads, no permissions (and no promises on being "pretty").

FAQ

Does it track wifi usage, or just mobile?
Mobile usage only.

Does the usage history continue if the device restarts?
No, usage tracking resets when the phone is started.

Can I turn off the "always on" notification?
Yes. Long-hold the notification, and Android will let you customize which notifications to display for the app. Do not disable all categories, as then you can't get notified of spikes!

How accurate is usage tracking?
To maximize device/battery performance, the monitor checks usage periodically and tracks it in "time buckets". Recent usage is tracked in 1-minute buckets, increasing to 1-day buckets for the oldest usage.

A side-effect of these buckets is that usage is averaged over the bucket time, so alarms with a time window of more than a few hours may not trigger at the exact minute or usage as expected. For instance, a 50MB download yesterday is not tracked at a precise second, but may be treated as spread evenly over a 1-hour period.

My alarm just triggered. How do I find the cause?
Click the View Usage button to open your device's standard "Data usage" app. From there you may have a "Mobile usage" button to see a detailed breakdown of which apps have consumed the most data.

What's the differences between the Free and Paid versions?
The free version (link) does not automatically start when the phone starts. The paid version (link) does.

I would love if the app also did ___. Can you build it?
Perhaps. Feel free to send requests and feedback to [email protected]!