Racing Slips vs HowFast
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Racing Slips
Record and access your drag racing time slips digitally. Calculate density altitude to predict your next ET dial and eliminate the need for paper slips. View qualification, pairing, and ladder reports easily.
- Digital time slip recording
- Density altitude calculation
- ET dial prediction
- Qualification reports
- Pairing reports
- Ladder reports
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Use our app to view your Drag Racing Time Slips! Our app also record your density altitude at the time of your race so you can use the data to predict your next ET dial. No more paper to go through, all your racing time slips in the palm of your hand using your iPhone or iPad! Access all the qualification, pairing and ladder reports using our TimeSlip app! This app can be used at the Napierville Dragway Tracks in Québec. You can review our "Terms of Use" here: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ You can review our "Privacy Policy" here: https://www.dynogeeks.com/privacy.html
HowFast
Predict your drag race elapsed times with real vehicle specs and atmospheric conditions. The app learns from your runs to improve accuracy and logs every pass for detailed analysis. Upgrade for advanced features like OBD-II connectivity and multi-run comparisons.
- Elapsed time prediction
- Real-time density altitude correction
- Automatic run detection
- Run history logbook
- Export to DynoLog
- OBD-II connectivity (Pro)
- Multi-run comparison (Pro)
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Know your number before you stage. HowFast predicts your elapsed time using your vehicle's real specs — engine, drivetrain, tires, and the air conditions at your track. Whether you're dialing in for bracket racing or just curious how quick your car really is, HowFast gives you a data-driven starting point that gets smarter every time you run. Predict with confidence HowFast builds your ET prediction from the ground up — horsepower, drivetrain loss, tire grip, shift times, and real-time density altitude correction. The more you run, the more accurate it gets. HowFast learns from your actual timeslips and adjusts future predictions automatically. Built for the track, not the spec sheet! No expensive GPS hardware required. Use your iPhone's built-in GPS for run detection and timing, or connect to a RaceBox or Qstarz external GPS unit for precision timing at up to 25Hz. HowFast automatically detects your run and starts logging — no tapping required. Your logbook, is always with you! Every run is saved with your predicted ET, actual ET, speed, and conditions. Review your history, spot trends, and see how your tune is progressing over the season. Export Every Run in the DynoLog app effortlessly! HowFast captures your ET, trap speed, 60-foot time, and atmospheric data at the strip. DynoLog is where that data becomes a permanent part of your build record — plotted on a performance timeline, correlated to every mod you've made, and exportable as a professional PDF build sheet. After your pass, tap Export to DynoLog or login and the run lands in your build log automatically — no manual entry, no duplicate imports, no data left behind. Upgrade to Pro — one time purchase, yours forever. Unlock the full HowFast experience with a single one-time purchase: OBD-II connectivity— see your RPM, TPS, gear you're in, in real time Multi-run comparison — overlay runs and telemetry to find where you're gaining or losing Unlimited vehicles in your garage CSV export — take your data anywhere HowFast Pro is a one-time purchase. No subscription, no recurring charges. Whether you're a seasoned bracket racer chasing a perfect dial or a weekend warrior seeing what your car can do, HowFast is the smartest co-driver you've never had.
Screenshots
Verdict
The clearest difference is ads: Racing Slips at none against HowFast's shown. Racing Slips also leads on update cadence (every 4 days vs every 3 weeks) and iOS requirement (15.6 vs 26.2). HowFast's advantage is ratings volume (3 vs 1). On price, rating, 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
Both are free to download. Racing Slips sells 2 in-app purchases, starting at $4.99 per month and HowFast sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 5.0 for Racing Slips against 5.0 for HowFast. Both are backed by a comparable volume of ratings — 1 and 3 respectively.
Racing Slips ships an update every 4 days, HowFast every 3 weeks. The most recent releases landed on October 14, 2026 and October 12, 2026 respectively.
| Parameter | Racing Slips | HowFast |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) | 5.0 (3 ratings) |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | 1 | 3 — better |
| Update frequency | Every 4 days — better | Every 3 weeks |
| Ads | No — better | Yes |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.6 — better | 26.2 |
| Further details — not scored | ||
| Size | 19 MB | 15 MB |
| Age rating | 4+ | 12+ |
| Developer | Stephan Monette | DtimesTwo Technologies LLC |
Customer experience
Racing Slips
HowFast
In-app purchases
Racing Slips
- Premium Sharing$4.991 Month
- Annual Premium Access$8.991 Year
HowFast
- HowFast Pro$7.99









