HowFast vs GoSlips
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
GoSlips
View live drag racing time slips directly on your phone. Track elapsed time, reaction time, speed, and more as races happen. Follow events from anywhere, whether you're at the track or at home.
- Live time slip viewing
- Real-time race data
- Track switching
- Search past slips
- Follow from any location
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GoSlips brings live drag racing time slips to your phone. Choose your track and watch results appear as they happen, including elapsed time, reaction time, dial-in, speed, and the rest of the slip, so you never miss a run. Browse the live feed, search past slips, and switch tracks anytime. Whether you’re in the stands, the pits, or following from home, GoSlips keeps every pass in one place so you can track the race as it unfolds. Whether you’re in the stands, the pits, or following from home, GoSlips keeps every pass in one place so you can track the race as it unfolds.
Screenshots
Verdict
The clearest difference is in-app purchases: GoSlips at none against HowFast's 1. GoSlips also leads on ads (none vs shown) and ratings volume (49 vs 3). On price, rating, update cadence 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
Both are free to download. HowFast sells 1 one-off in-app purchase. GoSlips asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 5.0 for HowFast against 4.9 for GoSlips. That said, the two scores are not equally well evidenced: GoSlips has 49 ratings behind it against 3, so its average is the more settled of the two.
HowFast ships an update every 3 weeks, GoSlips every 10 days. The most recent releases landed on October 12, 2026 and October 25, 2026 respectively.
| Parameter | HowFast | GoSlips |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (3 ratings) — better | 4.9 (49 ratings) |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 3 | 49 — better |
| Update frequency | Every 3 weeks | Every 10 days — better |
| Ads | Yes | No — better |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 26.2 | 15.0 — better |
| Further details — not scored | ||
| Size | 15 MB | 37 MB |
| Age rating | 12+ | 4+ |
| Developer | DtimesTwo Technologies LLC | Logan Back |
Customer experience
HowFast
GoSlips
In-app purchases
HowFast
- HowFast Pro$7.99
GoSlips
No in-app purchases









