Engine RPM vs Motool Service Assistant
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Engine RPM
Analyze engine sound to calculate RPM using advanced signal processing. Ideal for engine setup and diagnostics, it supports various engine types and provides real-time feedback for accurate readings.
- Acoustic RPM measurement
- Engine sound analysis
- Supports 2-stroke/4-stroke engines
- Configurable cylinder count
- Real-time autocorrelation graph
- Adjustable update periods
- Low-pass filtering
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Measure the RPM of an engine by analyzing the sound it makes. Engine RPM listens to the sound of a running engine and uses advanced signal processing algorithms to extract the frequency of that sound and calculate the RPM. This app is primarily for setup and diagnostics of engines. After setting the the number of cylinders and whether the engine is a 2-stroke or 4-stroke engine, the app can work with any internal combustion engine, from diesel tractors to aircraft engines to motorcycles to chainsaws. To use the app you must set an expected RPM range to guide the analysis algorithms to the correct RPM. A real-time graph of the autocorrelation graph is displayed to help in troubleshooting and adjusting the expected RPM range. The analysis requires a clear sound from the engine without excessive interference from extraneous sounds. Do not expect to read the RPM of an engine while other things are making too much noise at the same time. The analysis also requires that the RPM be stable. It cannot read the RPM of an engine that is rapidly accelerating. For this reason, and because of the need for adjusting the expected RPM range, this app should not be considered a drop-in replacement for an operational tachometer. Setup options include update periods from 93 milliseconds to 1.5 seconds, one to 12 cylinders, 2-stroke or 4-stroke, low-pass filtering, and signal clipping. The overall RPM range is 400 to 90,000 RPM (although at any one time, the operational range is typically +/- 30% around a nominal expected RPM). Precision is usually about +/- 10 RPM.
Motool Service Assistant
This app helps motorcycle and mountain bike owners track maintenance tasks, log suspension settings, and record ride notes. It offers reminders for upcoming services and supports managing multiple bikes. An optional subscription unlocks advanced features and a virtual remote display.
- Service task tracking
- Suspension setting logs
- Ride notes documentation
- Service interval reminders
- Unlimited bike management
- Virtual remote display
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Your whole garage in your pocket. Save every bike, log every setting, and watch service intervals tick down as the hours and miles add up, so nothing sneaks up on you. Service Assistant is the setup and maintenance logbook for people who work on their own bikes- dirt, street, ADV, or MTB. Add a motorcycle or mountain bike, save its baseline settings, then build a record you can trust instead of trying to remember what you changed three rides ago. A SERVICE CENTER THAT COUNTS DOWN FOR YOU Set the intervals that matter to you the most- suspension service every 40 hours, tune-up every 15 hours, chain every 300 miles. After a ride, log your hours or mileage once. Service Assistant subtracts from every interval automatically and tells you what's coming due before it becomes a problem. You can track by mileage or runtime depending on the bike type. Engine, suspension, chassis, brakes, electrical, drivetrain: if it runs on a schedule, you can track it here. SETTINGS YOU CAN ACTUALLY FIND AGAIN Save a baseline for every bike, then log what you change as you dial it in. Clicker positions, sag, spring rates, tire pressure, gearing, bar and lever position. Record it, compare it, and get back to it when a setup change doesn't pan out. KEY FEATURES • Unlimited bikes — a full profile for every machine you own or maintain • Baseline settings — the known-good starting point you can always return to • Setup notes — suspension, tire pressure, ergonomics, conditions, results • Custom service intervals — by engine hours or mileage, set however you want • Automatic countdown — add hours or miles once, every interval updates • Complete service history — what you did, when you did it, on which bike • Slacker Virtual Remote — turns your phone into a large, easy-to-read display for the Slacker digital sag scale BUILT FOR RIDERS AND THE SHOPS THAT KEEP THEM RUNNING Whether it's one bike in the garage or a rack of customer machines, everything lives in one place — searchable, organized, and there the next time you need it. FROM THE MAKERS OF SLACKER Service Assistant is built by Motool, the team behind the Slacker digital sag scale — the patented suspension setup tool trusted by riders, tuners, and shops since 2014. Start with a 30-day free trial. $0.99/month or $9.99/year after that. — Payment will be charged to your Apple Account at the end of the 30-day free trial. Subscriptions renew automatically unless canceled at least 24 hours before the end of the current period. Manage or cancel your subscription anytime in your Apple Account settings. Any unused portion of a free trial is forfeited when you purchase a subscription. Terms of Service: https://getslacker.com/pages/terms-and-conditions Privacy Policy: https://getslacker.com/pages/privacy-policy
Screenshots
Verdict
The clearest difference is price: Motool Service Assistant at Free against Engine RPM's $8.99. Motool Service Assistant also leads on update cadence (every 8 days vs every 26 months). Engine RPM's advantage is rating (4.0 vs 3.3) and in-app purchases (none vs 2). On ratings volume, ads, device support and iOS requirement 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
Motool Service Assistant is free to download; Engine RPM costs $8.99 up front. Motool Service Assistant sells 2 in-app purchases, starting at $0.99 per month. Engine RPM asks for nothing beyond the download.
Engine RPM holds the better App Store score, 4.0 against 3.3. Both are backed by a comparable volume of ratings — 35 and 24 respectively. Written reviews point the same way: 48% of Engine RPM's written reviews are positive against 32% of Motool Service Assistant's.
Engine RPM ships an update every 26 months, Motool Service Assistant every 8 days. The most recent releases landed on September 19, 2026 and September 20, 2026 respectively.
| Parameter | Engine RPM | Motool Service Assistant |
|---|---|---|
| Price | $8.99 | Free — better |
| Rating | 4.0 (35 ratings) — better | 3.3 (24 ratings) |
| Positive reviews | 48.4% of reviews — better | 31.6% of reviews |
| Number of ratings | 35 — better | 24 |
| Update frequency | Every 26 months | Every 8 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 13.0 | 13.0 |
| Further details — not scored | ||
| Size | 3 MB | 233 MB |
| Age rating | 4+ | 4+ |
| Developer | Real-Time Specialties | Motool Inc |
Customer experience
Engine RPM
Motool Service Assistant
In-app purchases
Engine RPM
No in-app purchases
Motool Service Assistant
- Service Assistant1 Month trial$0.991 Month
- Service Assistant1 Month trial$9.991 Year
Questions
Is Engine RPM free?
Is Motool Service Assistant free?
Which has better reviews, Engine RPM or Motool Service Assistant?
Do Engine RPM or Motool Service Assistant have ads?
Which is updated more often, Engine RPM or Motool Service Assistant?
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