Comparison

Slow Them Down vs TayScan

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

Head to head
About

Slow Them Down

This tool transforms your iPhone into a traffic speed study device. Record passing vehicles, mark their positions frame by frame, and obtain precise speed estimates. Generate detailed reports for community advocacy and traffic calming initiatives.

Highlights
  • Record passing traffic videos
  • Frame-by-frame vehicle position marking
  • Accurate speed estimation (MPH)
  • Log vehicle type, direction, and timestamp
  • Generate PDF traffic reports
  • Automatic face and license plate blurring
  • Data for traffic calming advocacy
Features
Read full description

Slow Them Down turns your iPhone into a traffic speed study tool. Record vehicles on your street, mark their positions frame by frame, and get accurate speed estimates — no radar gun required. How it works 1. Calibrate your camera using a known reference distance (vehicle length, lane width, or a manual measurement) 2. Record a video of passing traffic 3. Select two frames and mark the vehicle's position in each 4. Get an instant speed estimate in MPH Track every vehicle Log each measurement with vehicle type, travel direction, street name, and timestamp. Build a complete picture of traffic patterns in your neighborhood over days, weeks, or months. Automated reports Generate detailed PDF reports with V85 speeds, traffic volume breakdowns, speed distribution charts, and vehicle type summaries. Filter by street to isolate problem areas. Share reports directly with your city council, HOA, or neighborhood group. Privacy built in Faces and license plates are automatically detected and blurred before you share anything. The app errs on the side of caution because a blurred street sign is better than a visible plate. We also don't store the images, videos beyond the processing needed to calculate a speed. Built for advocacy Speed data is what cities use to justify traffic calming measures like speed bumps, stop signs, and road diets. Slow Them Down gives your community the same data, collected from the streets you actually live on.

About

TayScan

Features
Read full description

Unlock Advanced Telemetry & Diagnostics for Your Porsche Taycan EV TayScan gives Taycan owners, enthusiasts, and independent specialists deep insights into their high-voltage battery system, real-time vehicle telemetry, and fault management—all directly via a Bluetooth OBD-II adapter. Key Features: • Battery Health & SoH Reports Generate official-style PDF Diagnostic Certificates detailing true State of Health (SoH), Max Usable Capacity (kWh), cell balance, and charging performance limits. Ideal for long-term health tracking or pre-purchase inspections (PPI). • Real-Time Telemetry & Fast-Charge Monitoring Track high-voltage pack voltage, cell span limits, average pack temperature, and real-time pre-conditioning status to ensure peak 270 kW DC fast-charging performance. • Cell Voltage & Imbalance Matrix Visualize individual cell voltages and track pack drift down to the millivolt (mV) level to verify anode-cathode balancing and pack integrity. • OBD-II Fault Code Scanner Quickly scan for Diagnostic Trouble Codes (DTCs) across battery management systems and vehicle gateways, inspect error details, and clear fault codes instantly. • 100% Private & Direct All vehicle queries run locally on your device via low-latency UDS commands. No account registration, subscriptions, or cloud servers required. • Built-in Vehicle Simulator Explore all telemetry screens and preview diagnostic metrics in Demo Mode without needing a physical vehicle connected. Supported Bluetooth (BLE) Adapters: - Vgate: iCar Pro BLE, vLinker MC+, vLinker BM+ - OBDLink: OBDLink CX, OBDLink MX+ (BLE mode) - Veepeak: OBDCheck BLE, OBDCheck BLE+ - Carista: OBD2 BLE Adapter - LELink: LELink / LELink2 - Generic BLE: Any standard ELM327 BLE 4.0+ adapter Support & Feedback: Have questions or want to request support for your specific adapter? Reach out to us directly at feedback@tayscan.nl. Disclaimer: TayScan is an independent diagnostic application. Porsche and Taycan are registered trademarks of Dr. Ing. h.c. F. Porsche AG. TayScan is not affiliated with or endorsed by Porsche AG.

Screenshots

Slow Them Down4 screens
TayScan3 screens

Verdict

The call

The clearest difference is iOS requirement: Slow Them Down at 17.0 against TayScan's 26.5. On price, ads, in-app purchases and device support 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.

Scorecard1 real difference · 9 level
Slow Them Down versus TayScan: the parameters behind the verdict, then further details
ParameterSlow Them DownTayScan
PriceFreeFree
Rating3.0 (2 ratings) — better—
Positive reviews100.0% of reviews—
Number of ratings2 — better—
Update frequencyEvery 2 months—
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhoneiPhone, iPad — better
Requires iOS17.0 — better26.5
Further details — not scored
Size4 MB9 MB
Age rating12+4+
DeveloperDuncan GrazierNiels Hollatz

In-app purchases

None

Slow Them Down

No in-app purchases

None

TayScan

No in-app purchases

Questions

Is Slow Them Down free?
Slow Them Down is free to download, with no in-app purchases.
Is TayScan free?
TayScan is free to download, with no in-app purchases.
Do Slow Them Down or TayScan have ads?
Neither Slow Them Down nor TayScan shows ads.

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