Sona Mobile vs NASA TLX
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Sona Mobile
This mobile application grants users access to the Sona Systems platform. It is designed for participants, researchers, and principal investigators, requiring the specific URL of a Sona site for functionality.
- Access Sona Systems
- For participants
- For researchers
- For principal investigators
- Requires Sona site URL
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This app provides access to Sona Systems for users of the system. It works for participant users, researchers and principal investigators. You will need to know the URL of your Sona site in order to use this app.
NASA TLX
This app provides a digital tool for researchers to measure subjective workload across various industries. It utilizes a multi-dimensional rating procedure based on six sub-scales to derive an overall workload score. Designed for flexibility, it allows for mobile and contextual assessments, ensuring data privacy and offline usability.
- Subjective workload measurement
- Six sub-scale rating procedure
- Anonymized data collection
- Offline assessment capability
- QR code study setup
- Location flexibility
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The Official NASA Task Load Index (TLX) App, widely regarded as the gold standard for measuring subjective workload across a wide range of industries, enables researchers to easily perform assessments on operators working with various human-machine interface systems. By incorporating a multi-dimensional rating procedure, the NASA TLX derives an overall workload score based on a weighted average of ratings on six sub scales: ∙ Mental Demand ∙ Physical Demand ∙ Temporal Demand ∙ Performance ∙ Effort ∙ Frustration Originally developed as a paper and pencil questionnaire by NASA Ames Research Center’s (ARC) Sandra Hart in the 1980s, the NASA TLX is the benchmark against which the efficacy of other measures, theories, or models are judged. The NASA TLX has been successfully used around the world to assess workload in various environments such as aircraft cockpits; command, control, and communication (C3) workstations; supervisory and process control; and simulations and laboratory tests. The NASA TLX app for iOS dramatically increases the outreach and accessibility for the research and development community, and enables mobile and contextual assessments (e.g., in an airplane cockpit during/after flight, rather than at a desktop computer in a lab). It offers several key features that benefits both researchers and participants: Privacy The NASA TLX has been designed to ensure the privacy of research participant data. The NASA TLX anonymizes all results and does not send any personal identifiable information (PII) to any data servers. Location Flexibility The NASA TLX app can be used anywhere, even without a network connection, so researchers can have participants complete a NASA TLX evaluation in the field, outside the confines of a desktop office environment. The NASA TLX results are calculated on the device, and, once a network connection is available, collected data can be securely uploaded to servers for analysis. This frees researchers from being burdened by the task of tracking individual paper forms. Simple Study Setup Researchers can set up studies quickly and reduce typing on the NASA TLX app by scanning a pre-generated QR code from within the app, which automatically populates the study name, subject ID, and trial number in the app.
Screenshots
Verdict
The clearest difference is rating: NASA TLX at 3.5 against Sona Mobile's 2.7. NASA TLX also leads on iOS requirement (10.0 vs 15.1). Sona Mobile's advantage is review sentiment (20% vs 11%). On price, ratings volume, update cadence and ads 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
NASA TLX holds the better App Store score, 3.5 against 2.7. Both are backed by a comparable volume of ratings — 10 and 11 respectively. Written reviews complicate that: 20% of Sona Mobile's written reviews are positive against 11% of NASA TLX's, so the app with the better star average is not the one people write more warmly about.
Both ship on a similar rhythm, roughly every 3 months. The most recent releases landed on October 7, 2026 and October 24, 2026 respectively.
| Parameter | Sona Mobile | NASA TLX |
|---|---|---|
| Price | Free | Free |
| Rating | 2.7 (10 ratings) | 3.5 (11 ratings) — better |
| Positive reviews | 20.0% of reviews — better | 11.1% of reviews |
| Number of ratings | 10 | 11 — better |
| Update frequency | Every 3 months | Every 3 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.1 | 10.0 — better |
| Further details — not scored | ||
| Size | 38 MB | 17 MB |
| Age rating | 4+ | 4+ |
| Developer | Sona Systems | NASA |
Customer experience
Sona Mobile
NASA TLX
In-app purchases
Sona Mobile
No in-app purchases
NASA TLX
No in-app purchases









