iVSP vs RocControl
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
iVSP
Experience ship navigation with Voith propulsion systems. Explore the mechanics and hydrodynamics of Voith Schneider Propellers (VSP) and their unique thrust capabilities on various vessel types. Learn about the innovative technology behind this propulsion system.
- Steer ships with Voith propulsion
- Explore Voith Schneider Propeller mechanics
- Understand VSP hydrodynamics
- Simulate various vessel types
- Learn about VSP thrust generation
Read full descriptionHide full description
The iVSP app allows users to steer ships equipped with Voith propulsion systems, in particular Voith Schneider Propeller (VSP). These are real ships of various types: Voith Water Tractors (tugs), double-ended ferries, offshore vessels, and yachts. iVSP also provides a deeper insight into the mechanics and hydrodynamics of the Voith Schneider Propeller (VSP) and its unique propeller forces. The VSP enables the fastest generation of thrust in all directions – stepless and precisely. VSPs combine propulsion, steering, and roll stabilization in a single unit, eliminating the need for rudders. Thrust and steering forces can be generated in any direction from zero to maximum. The Voith Schneider Propeller generates thrust by means of profiled blades that protrude from the ship's bottom and rotate around a vertical axis. The blades are mounted in a rotor casing that is flush with the ship's bottom. The rotational movement of the blades around the common vertical axis is superimposed by a local oscillatory movement of the individual propeller blades around their own axis. This oscillatory movement is generated by a kinematic mechanism (kinematics). The Voith Schneider Propeller is based on an idea by Austrian inventor Ernst Schneider, and its effectiveness was first successfully demonstrated in model tests in 1926. The development potential of the VSP is far from exhausted, and Voith engineers are continuously working to further improve its efficiency. In addition, the company is constantly developing new applications for various types of ships for this unique propulsion system. Suggestions for the application and further improvement of the VSP are always welcome. The relevant contact details for Voith can be found in the main menu of iVSP.
RocControl
Control your digital model railroad layouts remotely. Manage locomotives, switches, and signals, and set trains to run automatically. Connect to a Rocrail server to operate your entire layout from your mobile device.
- Control locomotives, switches, and signals
- Automatic train operation
- Dialogs for blocks, turntables, and staging yards
- Dedicated locomotive throttle
- Layout, driving, and system control tabs
- Automatic connection to local Rocrail servers
Read full descriptionHide full description
The app controls digital model railroad layouts by driving locomotives, set switches, set signal, and let run trains automatically. This app is a mobile client for the model railroad program Rocrail. See https://wiki.rocrail.net for more information on Rocrail. The app offers dialogs for blocks, turntables, traversers, staging and fiddleyards; All you need to control your model railroad layout with a mobile device. A special dialog is the throttle for controlling locomotives speed and functions. The app has 3 main tabs: One for the layout, one for driving and one for the system controls and tracing. In order to control a model railroad layout the app must be connected to a Rocrail server. If one is found on the local network, mDNS/Bonjour, it will automatically connect to it. The Rocrail Demo server can be connected if no local server has been found. This option is available in the Settings menu, the gear symbol right on top, if no local server has been found.
Screenshots
Verdict
The clearest difference is review sentiment: iVSP at 100% against RocControl's 50%. iVSP also leads on iOS requirement (13.0 vs 16.6). RocControl's advantage is update cadence (fortnightly vs every 21 months). On price, ads, 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. Neither carries in-app purchases, so what you see is what you pay.
iVSP ships an update every 21 months, RocControl fortnightly. The most recent releases landed on October 15, 2026 and September 30, 2026 respectively.
| Parameter | iVSP | RocControl |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | — |
| Positive reviews | 100.0% of reviews — better | 50.0% of reviews |
| Number of ratings | 1 — better | — |
| Update frequency | Every 21 months | Fortnightly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Apple Watch |
| Requires iOS | 13.0 — better | 16.6 |
| Further details — not scored | ||
| Size | 384 MB | 4 MB |
| Age rating | 4+ | 4+ |
| Developer | Voith Digital Solutions Inc | Rocrail |
Customer experience
iVSP
RocControl
In-app purchases
iVSP
No in-app purchases
RocControl
No in-app purchases









