OVSICORI-UNA Alerta Terremotos

Review by eFreeware

Most earthquake apps are really information apps: they tell you what happened after the shaking stops. This one tries to do the opposite. It is built to give you a few seconds of notice before a quake reaches you, using the early warning system run by OVSICORI-UNA, and it does that through three graded alert levels rather than a single generic notification. That difference in purpose is the whole reason to consider it.

It is aimed at people who live, work or travel within the zone the system actually covers, and who want an official signal on their phone rather than a general feed of seismic news. If you are in that group, the appeal is straightforward: a warning that arrives early enough to matter, delivered in a form you can act on without reading anything.

The app is free, carries no ads and offers no in-app purchases. It sits in the Education category on Google Play, has been installed more than 100,000 times and holds a 4.2 average from 1,279 ratings. It was released on July 5, 2023, and last updated on March 5, 2025.

Three alert levels, three different responses

The core of the app is a tiered warning system. A Red Alert means the earthquake may be felt at an intensity of V or higher, and it is the one that matters most: the developer says it gives you a few seconds to take protective action. It arrives as a voice command plus vibration, which is a sensible choice for a moment when you may not be looking at the screen.

An Orange Alert covers events expected to be felt at intensity III up to but not including V. That one comes through as sound and vibration, so it is noticeable without being as urgent as the red case. A Green Alert is for quakes below intensity III and is delivered silently, which keeps the app from shouting at you over tremors that are unlikely to cause trouble.

What I like about this arrangement is that the notification style carries meaning before you read a word. A voice telling you to act, a sound that gets your attention, or silence: you can tell roughly what you are dealing with from the alert itself. The protective action the app is designed around is the standard one of crouching, protecting yourself and waiting.

For each event, the app also lets you report what you perceived or felt. That reporting option turns a one-way warning into something closer to a two-way record, and it is the kind of detail that gives the system feedback from the ground.

Where the warning actually works

The most important thing to understand before installing is the range. The developer is explicit that the app is effective only at distances of roughly 50 to 150 km from the earthquake. Closer than that, there is no time to issue a warning; farther away, the quake may still be felt but is not expected to cause damage significant enough to justify an alert.

That band is narrower than people often assume when they hear the phrase early warning. It means the app is not a general-purpose seismic notifier for an entire country, and it is not a substitute for standard preparedness. It is a tool for a specific distance window, and its usefulness depends on where you happen to be when something happens.

The National University runs the service alongside OVSICORI-UNA's existing information work. That institutional backing is part of the value here: the alerts come from an official monitoring operation rather than a private hobby project.

The developer also describes the system as fully automated, linking multiple instruments and algorithms. That is what makes fast warnings possible, and it is also why the app is susceptible to technical failures. An automated chain has no human in the loop to catch a bad reading before it reaches your phone.

What it asks of you

The app is free to install and use, with no advertising and no purchases to consider. Alerts arrive without any setup. The cost here is not money; it is attention.

A warning system only works if it can reach you, which means the phone needs to be on and able to receive the notification. The seconds a Red Alert buys you are only useful if you already know what you plan to do with them, so the practical preparation happens before any alert arrives, not during one.

It is also worth setting expectations about reliability. The developer notes that automated instruments and algorithms can fail. I would treat any single alert as a strong signal rather than an infallible one, and treat the absence of an alert as no signal at all.

Finally, the reporting feature asks something of you after the fact. Taking a moment to record what you felt helps build a picture of each event, and it is a small contribution that fits naturally into the app's purpose.

How I would use it

The sensible approach is to install it, leave notifications enabled and then forget about it until it speaks. This is not an app you open daily; it is one that should sit quietly in the background and earn its place in the handful of seconds that matter.

Because the effective range is limited, it helps to know roughly where you stand relative to those distances. If you spend most of your time well outside that window, the app will rarely have anything useful to tell you, and that is a function of physics rather than a flaw in the software.

I would also pair it with a plan rather than relying on the alert alone. Knowing in advance where you would crouch, what you would protect yourself with and how long you would wait turns a few seconds of warning into something you can actually use. The app supplies the notice; the response is yours.

And when a quake does pass, filing a report is worth the minute it takes. It is the one part of the app where you contribute rather than receive, and it feeds the same system that warned you.

A narrow tool that does one job

This is not a rich app, and it does not try to be. What there is, is a direct line from an official monitoring service to your phone, expressed in three clearly differentiated alert levels and backed by a reporting option.

The trade-off is built in. The same automation that makes fast warnings possible also makes the system fallible, and the 50 to 150 km window means the app is only relevant in a specific set of circumstances. Anyone expecting blanket coverage of every tremor they might feel will be disappointed by how the physics works.

What I find persuasive is the honesty of the design. The alert levels map to intensity thresholds, the notification style changes with severity, and the range limits are stated up front rather than glossed over. For a safety tool, that clarity matters more than feature count.

A strong pick for residents inside the warning zone

I would recommend this app to people who live, work or regularly spend time within the distance band where the early warning system operates. For them, it offers something few apps can: a few seconds of official notice, delivered in a form designed to be understood instantly, at no cost and with no ads or purchases in the way.

It also suits anyone who wants their earthquake information to come from an institutional source rather than a crowdsourced feed. The National University connection and the OVSICORI-UNA name behind it are the reason to trust the alerts at all.

It is less useful for people who are rarely inside that range, and it should not be mistaken for a complete preparedness solution. The app gives you a warning; what you do with the seconds it provides is still up to you.

As a free, focused tool with a 4.2 average from more than a thousand ratings, it earns a place on the phone of anyone it can actually reach. Install it, enable notifications, learn what each alert means, and leave it alone until it matters.