Comparison

NASA PVT+ vs Lugna

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

Lugna

This guided journaling app helps you express thoughts and feelings through typing, speaking, or writing with a stylus. It provides insights into your well-being over time and offers daily reminders to encourage consistent journaling. Enhanced privacy is available with PIN and biometric app lock.

Highlights
  • Guided journaling with prompts
  • Speech-to-text and stylus input
  • Mood tracking and statistics
  • Customizable journaling reminders
  • PIN and biometric app lock
Features
Read full description

Lugna is a quiet, private place to write. It's for the days when your mind is full and you need somewhere to put it all down. Lugna helps you begin with gentle, guided questions, or simply lets you write freely. Over time it shows you how you've been feeling, so you can notice patterns, be kinder to yourself, and see how far you've come. And because your journal is yours, Lugna keeps it that way. Your entries are end-to-end encrypted. They're locked with a key that only you hold, not us and not anyone else. You can write honestly, knowing that what you put down stays with you. WHAT YOU CAN DO • WRITE THE WAY THAT FEELS RIGHT Follow guided CBT-inspired prompts when you'd like some direction, or open a blank page and let it pour out. Prefer to talk? Use dictation and speak your mind. • NEVER LOSE A THOUGHT Your draft is saved as you write, even if you switch apps, get interrupted, or your phone rings. Come back and your words are still there. • SEE HOW YOU'VE BEEN Weekly and monthly views show your mood over time, along with your journaling streak, so you can notice what lifts you and what weighs on you. • KEEP IT PRIVATE Protect Lugna with Face ID, Touch ID, or a PIN, and let it lock itself when you look away. Your journal stays behind that lock. • A GENTLE REMINDER Choose a time that suits you, and let Lugna remind you to slow down, check in, and write. • TAKE IT WITH YOU Save your entries whenever you like. Keep them somewhere safe, or share them with someone you trust, like your therapist or caregiver. You also hold a 12-word recovery phrase, like a spare key to your own journal, that only you have. Your mind deserves a safe place to rest. Lugna is that place.

Screenshots

NASA PVT+4 screens
Lugna4 screens

Verdict

The call

The clearest difference is rating: NASA PVT+ at 4.8 against Lugna's 2.0. NASA PVT+ also leads on review sentiment (25% vs 0%) and ratings volume (10 vs 1). Lugna's advantage is update cadence (weekly vs every 3 months). On price, ads, in-app purchases and monetization model 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 2.0. That said, the two scores are not equally well evidenced: NASA PVT+ has 10 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 25% of NASA PVT+'s written reviews are positive against 0% of Lugna's.

UpkeepUpdate frequency

NASA PVT+ ships an update every 3 months, Lugna weekly. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.

Scorecard5 real differences · 5 level
NASA PVT+ versus Lugna: the parameters behind the verdict, then further details
ParameterNASA PVT+Lugna
PriceFreeFree
Rating4.8 (10 ratings) — better2.0 (1 ratings)
Positive reviews25.0% of reviews — better0.0% of reviews
Number of ratings10 — better1
Update frequencyEvery 3 monthsWeekly — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS13.6 — better16.0
Further details — not scored
Size31 MB16 MB
Age rating4+4+
DeveloperNASARayhan Faluda

Customer experience

NASA PVT+

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

Lugna

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

NASA PVT+

No in-app purchases

None

Lugna

No in-app purchases

Questions

Is NASA PVT+ free?
NASA PVT+ is free to download, with no in-app purchases.
Is Lugna free?
Lugna is free to download, with no in-app purchases.
Which has better reviews, NASA PVT+ or Lugna?
NASA PVT+ is rated higher. NASA PVT+ averages 4.8 out of 5 from 10 ratings, while Lugna averages 2.0 from 1 ratings.
Do NASA PVT+ or Lugna have ads?
Neither NASA PVT+ nor Lugna shows ads.
Which is updated more often, NASA PVT+ or Lugna?
NASA PVT+ ships an update every 3 months, and Lugna weekly. Most recently, NASA PVT+ was updated on November 2, 2026 and Lugna on November 3, 2026.

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