Before the list, the most important information here: cell phones do not measure glucose. No smartphone has a sensor capable of measuring blood sugar, and no app replaces a glucometer test or a consultation with a healthcare professional. The apps in this article don't measure anything—they record. You take the measurement on the device, enter (or sync) the value, and the app takes care of the rest: history, graphs, medication reminders, and a report to take to the doctor.
Having made that distinction, the rest is advantageous. Managing diabetes is a daily and repetitive task, and having this record in your pocket changes the quality of the conversation in the doctor's office. Below are six apps that actually exist in official app stores, explaining what each one does and where to find them.
Beware of apps that promise to measure with your finger.
There are apps advertised as "glucose meters" that ask you to touch your finger to the camera with the flash on. What the camera captures is the variation in light caused by your pulse—at most, an estimate of your heart rate. Glucose doesn't appear in that reading. Any blood glucose value shown by one of these apps is a guess, it's not useful for making any decisions about treatment and can cause real harm if someone adjusts insulin based on that number.
Accurate measurement can only be achieved in two ways: with a glucometer, using a test strip and a drop of blood, or with a continuous monitoring sensor applied to the body and prescribed by a professional. A cell phone can, at most, read this sensor by proximity or receive data from the glucometer via Bluetooth.
mySugr
One of the world's most popular diabetes diaries, published in app stores as "mySugr — Control your diabetes!". You record your blood glucose levels measured by the device, your food intake, physical activity, and medication; the app organizes this data into graphs and allows you to export reports for consultation. It also shows an estimate of glycated hemoglobin calculated from the values you entered — an approximate reference that does not replace a laboratory test.
It's available on Google Play and the Brazilian App Store. It's free to download, but it has in-app purchases: the PRO version is a paid subscription.
Glyc – Diabetes and Blood Glucose
This Brazilian app, in Portuguese, formerly called GlicOnline, is used to record blood glucose levels, insulin doses, carbohydrates, and medications, with reminders at times you define. It generates graphs and reports that can be shown to the healthcare team, which is very helpful for those who are receiving treatment through the public health system (SUS) or private health insurance and want to have their medical history readily available.
Free on Google Play and the Brazilian App Store. Because it's in Portuguese and doesn't have excessive fields, it's usually the easiest for beginners.
Diabetes:M
From Sirma Medical Systems, this is the most comprehensive system in terms of the number of fields. It records blood glucose levels, meals, insulin doses, weight, and also blood pressure values measured by your blood pressure monitor. The reports are detailed, and there is a bolus calculator for those who use insulin and have received instructions on how to perform this calculation.
Available for free on Android and iPhone, with in-app purchases for advanced features. It's the choice for those who appreciate detail; those who prefer simplicity may find it overly busy with options.
Glucose Buddy
Azumio's Glucose Buddy combines blood glucose diarying with diet and exercise tracking. In addition to the measured value, you record meals, workouts, and medication, and the app cross-references this data into reports—useful for understanding blood glucose levels within the context of the day, not just as isolated numbers.
The basic app is free in both stores, with in-app purchases. The Brazilian App Store also has a separate, paid version, Glucose Buddy+ — it's worth checking which one you're downloading to avoid surprises.
MedM Glucose Diary
MedM offers a lean and straightforward option. It does one thing, and does it well: it keeps a blood glucose diary with date, time, and observations, and exports the history as a report. For those who only need to record the value and present the series to the doctor, without carbohydrate counting or insulin calculation, it's quicker to use daily.
It's available in both app stores and is free, with slightly different names: "Diabetes Glucose Diary" on Google Play and "MedM Glucose Diary" on the App Store.
OneTouch Reveal
This is the companion app for LifeScan's OneTouch glucometers. If your device is a Bluetooth-compatible model, it sends the measurement directly to your phone—without typing, which reduces transcription errors. The app compiles the history, marks values outside the range agreed upon with your doctor, and generates a report to share.
An honest observation: OneTouch Reveal is free on Google Play in Brazil, but it doesn't appear in the Brazilian App Store at the time of this publication. iPhone users need to use another app from the list to manually record measurements.
Conclusion
These six apps solve the same problem well, but in different ways: saving what has been measured and returning it in a useful format. The best one, without being romantic, is the one you'll open every day—a diary abandoned in its third week doesn't help anyone. Start simple and only migrate to a more complete app if you feel you're missing a specific field.
Always download from your device's official app store and be wary of APKs sent via messaging groups: they often contain health information. And the warning from the beginning still applies—this text is for informational purposes only and does not replace consultation, diagnosis, or treatment with a healthcare professional. No app measures glucose, and none of them will determine your treatment. Found outdated information? Write to [email protected].
How to make the record count for something in the consultation?
Writing down isolated numbers yields little results. What a professional can interpret is a pattern, and a pattern depends on three pieces of information recorded together.
- The price and the exact time. A blood glucose level of 180 at 8 am while fasting and the same level at 9 pm after dinner tell completely different stories.
- The context. On an empty stomach, before or after a meal, after physical activity, on a day of infection or stress. Almost all apps have this checkbox, and it's the most ignored.
- What was eaten, at least in post-meal measurements. Without that, a spike remains unexplained.
After a few weeks like this, what matters becomes apparent: at what time of day do the values fluctuate, which meals cause a spike, and whether there's an upward or downward trend throughout the month. It's this analysis that adjusts behavior—not yesterday's number.
Care should be taken with the measurement itself.
The app only saves what the glucometer reports. If the measurement is wrong, the entire history will be wrong.
- Wash and dry your hands thoroughly. Fruit or sugar residue on the finger is the most common cause of a meaningless high price.
- Check the expiration date of the tapes. And keep the bottle tightly closed. Strips exposed to moisture will give a false reading.
- Respect the temperature. as indicated by the manufacturer — extreme cold and heat affect the result.
- Alternate the puncture sites. so as not to always emphasize the same point.
- Discard the lancet. with each use; reusing increases pain and the risk of infection.
Continuous sensors: what changes
There are continuous monitoring sensors that are worn on the arm and send readings to a cell phone throughout the day. These are real, prescribed, and paid-for health devices, and they significantly change the way you track your condition—showing trends and the rate of change, not just the point at which you're monitoring it.
Two practical observations: they measure interstitial fluid, and therefore there is a slight delay compared to blood, which is mainly noticeable in rapid variations. And they do not replace the need for a finger prick in specific situations, according to the instructions of each manufacturer and the healthcare professional involved.
When to seek care
No app makes that judgment. Seek medical attention if:
- Very high levels accompanied by intense thirst, excessive urination, nausea, abdominal pain, or sweet-smelling breath.
- Signs of hypoglycemia — tremors, cold sweats, confusion, blurred vision — that do not improve after usual correction.
- Vomiting or inability to eat in those who use insulin.
- A foot wound that won't heal.
- Significant change in pattern with no apparent cause.
Any dose adjustment is a decision for whoever is following the case. The role of the record is to provide organized information for that conversation, never to replace it.
Privacy: a point that almost no one checks.
Blood glucose levels are health data, and health data is a sensitive category. Before choosing where to register, it's worth opening the privacy policy and looking for three things: whether there is sharing with third parties for advertising, whether it's possible to use it without linking to a social network, and whether there is an option to delete the entire history.
Also check the permissions requested during installation. A blood glucose diary doesn't need access to contacts, microphone, or precise location. And prefer those that export to PDF or spreadsheet — that way the history is yours and not tied to the app.
