Engine RPM vs MyVoltControl
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.
MyVoltControl
Enhance your Chevrolet Volt or Bolt experience with advanced control features. This app allows you to manage vehicle modes, monitor performance, and access diagnostic information, requiring an OBD adapter for full functionality.
- Vehicle information pages
- Simulated Hold mode for ICE management
- Engine run and off control
- Reset lifetime fuel economy
- EV and ICE travel distance calculation
- Diagnostic trouble code access
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MyVoltControl is designed specifically for the Chevrolet Volt (and related models), and the Chevrolet Bolt. ("Related models" include the Cadillac ELR, Cadillac CT6, Opel Ampera, Holden Volt, Opel Ampera-e.) MyVoltControl requires the use of an OBD adapter that complies with the ELM327 specification (most do). You can use either: - an OBDLink MX+ OBD adapter (preferred) - an OBDLink MX-WiFi OBD adapter - a Bluetooth-Low-Energy (aka Bluetooth 4) OBD adapter. (Classic bluetooth adapters are not supported by iOS.) - a generic WiFi OBD adapter will work in most cases (but is not recommended). If you need to buy an adapter, or to see a list of some that aren't ELM327 compatible, refer to the information in our FAQ page at http://www.CraftinDeApps.com/FAQ#MVC These adapters plug into the OBD-II port under the left side of your dash. The App itself is free. Use of the functions described below requires one-time in-app purchases to enable each one that you want to use. MyVoltControl consolidates four functions, long available for other phones, and makes them available for the iPhone and iPad. In addition, the last one is unique to this app. These are known as: -->> MyVoltHold -->> MyVoltLifetime -->> MyVoltDiag -->> MyVoltAfterblow -->> MyVolt12v -->> The Volt Hold function does four things. - First, at the top, it has several "information pages" that you can switch between to see information about your car. These are shown in the photos above. - Second, it allows you to turn on a "Hold" mode which approximates the Hold mode built into the car beginning with the 2013 model. This Hold mode turns on the internal combustion engine (ICE) as needed to try to maintain a State of Charge value that is close to the charge that was present when you turned the mode on. So why, you may ask, would I want that function on a newer car. Very simple really. Since Sport mode and Hold mode are mutually exclusive, this function allows you to use the car Mode button to engage Sport mode, while using the Hold function in this App to achieve Hold mode at the same time! Hold mode can also be automatically engaged based on several factors. - Next, it allows you to ask the car to run the internal combustion engine. You can use this to get heat from the engine on a cold morning, or to manually simulate your own Hold mode if you prefer. - Finally, you can also use this function to force the ICE off, which you might want to do if the ICE is running due to low temperature (done for driver comfort). The Volt Hold function is not available (and would serve no purpose) on the Chevrolet Bolt models. -->> The Volt Lifetime function allows you to reset the lifetime fuel economy value ("Lifetime MPG" or "Lifetime L/100km") value for your car. You will find this useful if you've purchased a car which has recorded the previous owner's fuel economy results. You can also use this to calculate the distance travelled in both EV mode and on the ICE by entering the Lifetime Economy number shown on your dash. The Volt Lifetime function is not available (and would serve no purpose) on the Chevrolet Bolt models. -->> The Volt Diag function allows you to run some tests on your high-voltage (traction) battery. -->> The Volt Afterblow function allows you to control a system that GM added to your car to dry out the A/C vents. This system is OFF by default and the Volt Afterblow function allows you to turn it on (or back off). This app function is not available for 2013 model year cars. - You can use the Volt Afterblow feature ONLY if you are using an OBD adapter which supports the SWCAN (aka GMLAN) bus. It must also support the "ST" command set (in addition to the common "AT" command set). Very few adapters offer this support. The known to be good and recommended adapters for this are the OBDLink MX+ or the OBDLink MX-Wifi adapters. -->> The Volt 12v function displays graphs showing the values of voltage and current on your 12 volt battery.
Screenshots
Verdict
The clearest difference is price: MyVoltControl at Free against Engine RPM's $8.99. MyVoltControl also leads on update cadence (every 5 weeks vs every 26 months) and rating (4.3 vs 4.0). Engine RPM's advantage is in-app purchases (none vs 5) and iOS requirement (13.0 vs 15.0). On review sentiment, ratings volume, ads 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
MyVoltControl is free to download; Engine RPM costs $8.99 up front. MyVoltControl sells 5 one-off in-app purchases. Engine RPM asks for nothing beyond the download.
MyVoltControl holds the better App Store score, 4.3 against 4.0. Both are backed by a comparable volume of ratings — 35 and 16 respectively. Written reviews point the same way: 48% of Engine RPM's written reviews are positive against 50% of MyVoltControl's.
Engine RPM ships an update every 26 months, MyVoltControl every 5 weeks. The most recent releases landed on September 19, 2026 and June 1, 2026 respectively.
| Parameter | Engine RPM | MyVoltControl |
|---|---|---|
| Price | $8.99 | Free — better |
| Rating | 4.0 (35 ratings) | 4.3 (16 ratings) — better |
| Positive reviews | 48.4% of reviews | 50.0% of reviews — better |
| Number of ratings | 35 — better | 16 |
| Update frequency | Every 26 months | Every 5 weeks — 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 — better | 15.0 |
| Further details — not scored | ||
| Size | 3 MB | 20 MB |
| Age rating | 4+ | 4+ |
| Developer | Real-Time Specialties | Craftin De Apps LLC |
Customer experience
Engine RPM
MyVoltControl
In-app purchases
Engine RPM
No in-app purchases
MyVoltControl
- Volt Hold Function$0.99
- Volt Lifetime Function$1.99
- Volt Diag Function$1.99
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- Volt 12v Function.$1.99
- Volt Afterblow Function$2.99
Questions
Is Engine RPM free?
Is MyVoltControl free?
Which has better reviews, Engine RPM or MyVoltControl?
Do Engine RPM or MyVoltControl have ads?
Which is updated more often, Engine RPM or MyVoltControl?
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