Comparison

FlickerSpec vs Bolt Torque Spec Calc

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

Head to head
About

FlickerSpec

Features
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Your new LEDs shouldn't be giving you headaches. If they are, the lights are almost certainly flickering — faster than your eyes can consciously detect, but fast enough to trigger migraines, eye strain, and fatigue. FlickerSpec turns your iPhone into a flicker meter, using the 240fps camera to measure exactly what your eyes can't. For documentation — clinical engineering, facility management, lighting audits — FlickerSpec generates PDF reports that record the IEEE 1789 result and IEC PstLM value together with the standard, threshold, measurement uncertainty and calibration reference behind them. FlickerSpec is a screening and documentation aid, not an accredited laboratory instrument; whether a report satisfies a particular surveyor or regulator is their determination. WHAT YOU MEASURE Quick Measurement (Free, unlimited) Live 240fps capture with real-time results: • Dominant flicker frequency in Hz • Percent Flicker and Flicker Index per IEEE 1789-2015 • Signal-to-noise ratio and confidence rating • Live luminance waveform and FFT spectrum • No daily limit — measure as many fixtures as you like IEEE 1789 Verdicts (Pro) Turn raw numbers into a documented decision: • IEEE 1789-2015 verdict against the published low-risk practice: PASS, FAIL, or Can't confirm when the capture or framing cannot support a pass • Custom pass/fail thresholds when your specification differs • The standard and threshold applied are recorded with every saved measurement 3-Minute PstLM Measurement (Pro) 3-minute tripod capture for documenting low-frequency flicker: • Short-Term Flicker Severity (PstLM) per IEC TR 61547-1:2015, for dominant frequencies up to 90 Hz • Compared against the PstLM ≤ 1.0 limit cited by EU Ecodesign 2019/2020 (PstLM only — Ecodesign also requires SVM, beyond FlickerSpec's 240fps phone-camera pipeline) • 8Ɨ oversampled LM flickermeter checked against all 5 IEC Table A.1 test vectors • Camera-based measurement aid, not an accredited instrument or certified result Measurement Logging & PDF Reports (Pro) Every audit, documented: • Save measurements with GPS location, fixture photo, and notes • Single-measurement and session-summary PDF reports • PstLM threshold-comparison section included when applicable • Calibration certificate reference on every report • CSV export for spreadsheet workflows Calibration System (Free) Verify accuracy before any audit: • Built-in calibration web app generates a known-frequency reference signal • Point your iPhone at any screen showing the calibration page • Timestamped calibration certificate attached to all subsequent reports MEASUREMENT BANDWIDTH 240fps camera capture (Nyquist: 120 Hz) is designed for 50 Hz mains regions: • 50 Hz and 100 Hz flicker (50 Hz mains) — frequency and modulation depth • 60 Hz and 120 Hz flicker (60 Hz mains, e.g. North America) — the dominant frequency may still be identifiable, but depth and the verdict that depends on it are conditional because 240 fps is an exact multiple of both. The app reports Can't confirm when it cannot sample the whole cycle. • Above 120 Hz PWM and kHz drivers — outside camera bandwidth • Modulation depth is a lower bound unless the light fills the region of interest NO SUBSCRIPTIONS $49.99 one-time purchase unlocks everything: IEEE 1789 risk indications, 3-Minute PstLM Measurement, unlimited logging, PDF reports, CSV export, the calibration certificate document, report header customization with your company name and logo. Free tier: unlimited Quick Measurements with the full live readout — frequency, percent flicker, flicker index, SNR and confidence — plus free calibration. Privacy Policy: https://flickerspec.slick-engineering.workers.dev/privacy Terms of Use: https://flickerspec.slick-engineering.workers.dev/terms

About

Bolt Torque Spec Calc

Features
Currently charting
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Built for mechanics, millwrights, and equipment installers who need bolt torque on the bench - not a desktop tool. WHAT IT DOES Looks up torque values for standard bolt sizes and grades using the T = K x D x F formula with K = 0.20. SAE grades 2, 5, and 8 across 28 sizes from #6-32 to 1-1/2 inch. Metric classes 4.6, 8.8, 10.9, and 12.9 across 17 sizes from M3 to M36. Dry vs. lubricated multiplier applied to the result. INPUTS - Standard: SAE or Metric - Bolt size (28 SAE or 17 metric sizes available) - Bolt grade or class - Lube condition: Dry or Lubricated RETURNS - Torque in ft-lb - Torque in NĀ·m CALCULATION BASIS - Torque formula: T = 0.20 x D x F - Preload F = 75% of proof strength times tensile stress area - Lubricated multiplier: 0.75 times the dry value WHY THIS APP, NOT THE FREE ONES - Math is shown - formula and assumed K factor visible, not hidden. - 45 size and grade combinations covered in one tap. - Works offline - shop floor, field repair, no Wi-Fi. Always available. - No login. No ads. No telemetry. No subscription. PRICING $1.99. Pay once, own it. Lifetime access on iPhone, iPad, and Mac via Family Sharing. NOT A SUBSTITUTE FOR Manufacturer-specified torque values for safety-critical fasteners. Calibrated wrench certificates. Specific K-factor adjustments for anti-seize, plating, or galvanized threads - this app uses K = 0.20 for both dry and lubricated, with the 0.75x multiplier as the only lube adjustment. Verify against the OEM tightening spec for the specific application.

Screenshots

FlickerSpec4 screens
Bolt Torque Spec Calc3 screens

Verdict

The call

The clearest difference is price: FlickerSpec at Free against Bolt Torque Spec Calc's $4.99. Bolt Torque Spec Calc's advantage is in-app purchases (none vs 1) and chart position (#195 vs unranked). On update cadence, ads and device support there is nothing between them.

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

CostPrice Ā· In-app purchases Ā· Ads Ā· Monetization

FlickerSpec is free to download; Bolt Torque Spec Calc costs $4.99 up front. FlickerSpec sells 1 one-off in-app purchase. Bolt Torque Spec Calc asks for nothing beyond the download.

UpkeepUpdate frequency

FlickerSpec ships an update every 4 weeks, Bolt Torque Spec Calc every 3 weeks. The most recent releases landed on October 13, 2026 and September 29, 2026 respectively.

Scorecard4 real differences Ā· 3 level
FlickerSpec versus Bolt Torque Spec Calc: the parameters behind the verdict, then further details
ParameterFlickerSpecBolt Torque Spec Calc
PriceFree — better$4.99
Update frequencyEvery 4 weeksEvery 3 weeks — better
AdsNoNo
In-app purchasesYesNo — better
Best chart rank—#195 — better
DevicesiPhoneiPhone, iPad — better
Requires iOS26.017.0 — better
Further details — not scored
Size12 MB1 MB
Age rating4+4+
DeveloperCorey Thomas SlickShanghai Sheyuan Network Technology Co., Ltd.

In-app purchases

1 purchases

FlickerSpec

One-time1
  • FlickerSpec Pro$49.99
None

Bolt Torque Spec Calc

No in-app purchases

Questions

Is FlickerSpec free?
FlickerSpec is free to download, with in-app purchases available.
Is Bolt Torque Spec Calc free?
Bolt Torque Spec Calc costs $4.99, with no in-app purchases.
Do FlickerSpec or Bolt Torque Spec Calc have ads?
Neither FlickerSpec nor Bolt Torque Spec Calc shows ads.
Which is updated more often, FlickerSpec or Bolt Torque Spec Calc?
FlickerSpec ships an update every 4 weeks, and Bolt Torque Spec Calc every 3 weeks. Most recently, FlickerSpec was updated on October 13, 2026 and Bolt Torque Spec Calc on September 29, 2026.

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