Comparison

NASA PVT+ vs AlertMeter

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

NASA PVT+

This app provides a validated tool for conducting psychomotor vigilance tests, crucial for sleep, alertness, and performance research. It offers multiple study frameworks, including simple tests, basic multi-day studies, and specialized aviation research protocols.

Highlights
  • Psychomotor Vigilance Test (PVT)
  • Karolinska Sleepiness Scale (KSS)
  • Sleep Diary
  • Simple PVT mode
  • Basic Study framework
  • Aviation Study framework
Features
Read full description

The official NASA PVT+ (Psychomotor Vigilance Test) is a validated iOS based touchscreen PVT that includes multiple industry standard research forms for collecting a wide range of research data for sleep, alertness and performance studies. The app has three principle data collection schemes designed to accomidate a wide range of research studies. The Simple PVT: The Simple PVT is a single presentation of the Psychomotor Vigilance Test (PVT; described below). Participants can be instructed to take a PVT at any time. There is no limit to the number of PVTs that a participant can take. Basic Study: The Basic Study provides a single or multiday pre-set framework for collecting research data. Participants are prompted to complete a sleep diary after their main sleep episode. The participant is then prompted to complete three PVT and Karolinska Sleepiness Scale (KSS) responses during the day. The participants also complete a sleep diary before bed. Aviation Study: The Aviation Study provides a multiday pre-set framework for collecting aviation related research data. Split into Off-Duty Days and Duty Days. Participants are prompted to complete a sleep diary after their main sleep episode. The participant is then prompted to complete three PVT and KSS responses during off-duty days. On duty days, the participant is prompted to complete a PVT and KSS pre- and post-duty. They are also prompted to complete a PVT, KSS, hassle factors, use of fatigue countermeasures, and inflight rest at the top of descent for each flight. The participants also complete a sleep diary before bed. The number of flights within a duty day can be adjusted. The aviation study also includes a pre-study baseline questionnaires that can be completed at study enrollment. The specific components of the application include: - Psychomotor Vigilance Test (PVT): A simple reaction-timed test that is sensitive to sleep loss and circadian misalignment. The PVT displays a box on the screen and participants are instructed to tap the screen with their dominant thumb when a millisecond counter appears in the box and begins to count up. After the participant taps the screen, the counter briefly displays the reaction time in milliseconds, then the counter disappears, and the participant is instructed to refrain from touching the screen until the next millisecond counter appears in the box. The counter appears randomly every 2 to 10 seconds. The PVT can be configured by the investigator to the desired duration (currently validated for a 5-minute test). - Karolinska Sleepiness Scale (KSS): The KSS is a self-reported sleepiness rating where the participant is asked to rate their level of sleepiness within the last five minutes on a scale from 1 to 9. - Sleep Diary: The Basic Study and Aviation Study each include a sleep diary that the study participant is prompted to complete at the beginning and at the end of the main sleep episode. The pre-sleep sleep diary asks the participant to record any naps that were taken prior to the main sleep episode, along with indicating the time of bedtime. The post-sleep sleep diary asks the participant to record the time that it took to fall asleep, number and duration of night awakenings, final wake time, and a sleep quality rating. - Study Enrollment Information: The Aviation Study includes a demographic questionnaire and the Morningness-Eveningness Questionnaire along with a practice sleep diary and practice PVT to orient the participant to study procedures. Data collected from study participants using the NASA PVT+ iOS application does not include Personally Identifiable Information (PII). Research data is never collected directly by NASA unless a volunteer is participating in a NASA study. Data collected for research studies conducted outside of NASA, through use of the NASA PVT+ application, is never sent to NASA without a specific agreement between the outside organization and NASA.

About

AlertMeter

This app helps identify when fatigue, illness, medication, or distraction may impact cognitive function. It allows individuals to regularly test their alertness levels, providing companies with a daily overview of employees in critical roles. The app is designed to respect employee privacy while assessing fitness for work.

Highlights
  • Personalized alertness testing
  • Company-wide daily overview
  • Privacy-respecting employee monitoring
  • Identifies impact of fatigue/illness
  • Assesses fitness for safety-critical roles
Features
Read full description

AlertMeter may help identify when fatigue, illness, medication, or distraction get in the way of a sharp state of mind. Developed for use by employees in a company setting, individuals test against their own personal alertness levels on a regular basis, providing companies with an all-company daily view of employees in safety-sensitive or quality-critical job roles. AlertMeter helps companies respect employee privacy as they check employees’ states of mind, a better measure of fit for work status than many current testing methods. For more information on how to use AlertMeter in your company, visit our website.

Screenshots

NASA PVT+4 screens
AlertMeter4 screens

Verdict

The call

The clearest difference is rating: NASA PVT+ at 4.8 against AlertMeter's 4.4. NASA PVT+ also leads on iOS requirement (13.6 vs 16.4). AlertMeter's advantage is review sentiment (50% vs 25%) and update cadence (monthly vs every 3 months). On price, ratings volume, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

NASA PVT+ holds the better App Store score, 4.8 against 4.4. Both are backed by a comparable volume of ratings — 10 and 15 respectively. Written reviews complicate that: 25% of NASA PVT+'s written reviews are positive against 50% of AlertMeter's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

NASA PVT+ ships an update every 3 months, AlertMeter monthly. The most recent releases landed on August 15, 2026 and September 8, 2026 respectively.

Scorecard4 real differences · 6 level
NASA PVT+ versus AlertMeter: the parameters behind the verdict, then further details
ParameterNASA PVT+AlertMeter
PriceFreeFree
Rating4.8 (10 ratings) — better4.4 (15 ratings)
Positive reviews25.0% of reviews50.0% of reviews — better
Number of ratings1015 — better
Update frequencyEvery 3 monthsMonthly — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS13.6 — better16.4
Further details — not scored
Size31 MB25 MB
Age rating4+4+
DeveloperNASAPredictive Safety SRP, Inc.

Customer experience

NASA PVT+

All ratings10 ratings
Positive90.0%
Neutral10.0%
Negative0.0%
Written reviews4 reviews
Positive25.0%
Neutral25.0%
Negative50.0%

AlertMeter

All ratings15 ratings
Positive80.0%
Neutral13.3%
Negative6.7%
Written reviews2 reviews
Positive50.0%
Neutral50.0%
Negative0.0%

In-app purchases

None

NASA PVT+

No in-app purchases

None

AlertMeter

No in-app purchases

Questions

Is NASA PVT+ free?
NASA PVT+ is free to download, with no in-app purchases.
Is AlertMeter free?
AlertMeter is free to download, with no in-app purchases.
Which has better reviews, NASA PVT+ or AlertMeter?
NASA PVT+ is rated higher. NASA PVT+ averages 4.8 out of 5 from 10 ratings, while AlertMeter averages 4.4 from 15 ratings.
Do NASA PVT+ or AlertMeter have ads?
Neither NASA PVT+ nor AlertMeter shows ads.
Which is updated more often, NASA PVT+ or AlertMeter?
NASA PVT+ ships an update every 3 months, and AlertMeter monthly. Most recently, NASA PVT+ was updated on August 15, 2026 and AlertMeter on September 8, 2026.

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