What Is a GNSS Surveying App?
Surveying with GPS or GNSS once required dedicated hardware, but today you can achieve high-precision positioning by combining a smartphone or tablet with an external GNSS receiver and a specialized surveying app. In particular, apps that support RTK (Real-Time Kinematic) can boost accuracy from several meters with standalone fixes to centimeter-level precision. This transformation has dramatically streamlined on-site stakeout and surveying workflows, changing the way surveys are conducted.

On the app’s interface, you’ll see the RTK fixed-solution status and the distance to your target displayed to the nearest centimeter, proving that high-precision positioning and navigation are possible even on a smartphone. Tasks that previously required professional equipment can now be performed easily with a phone and an app. With the rise of smartphone-based RTK positioning, anyone can now handle centimeter-level location data right in the field.

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The advantages of using RTK positioning on smartphones and tablets include the following:

• Portability and Ease of Use: A smartphone that fits in your pocket becomes the survey instrument itself, allowing you to perform positioning tasks instantly, anytime and anywhere. It’s much easier to carry than dedicated equipment and even enables one-person surveys in the field.

• Real-Time High-Precision Positioning: With the RTK method, you obtain centimeter-level positioning results in real time. For example, in network RTK, correction data received from a base station are applied instantly to compute highly accurate positions.

• Immediate Data Sharing: Because smartphones can easily connect to the Internet, you can upload positioning data to the cloud on the spot and share it with stakeholders. This eliminates the need to bring survey results back to the office for processing and enables real-time reporting and verification.

• Cost Efficiency: Compared to dedicated GNSS surveying equipment, pairing a general-purpose smartphone with a receiver can lower initial investment costs. You can leverage a smartphone you already own and choose from free or low-cost apps.

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So, what specific features do these GNSS surveying apps offer? The key points are as follows:

• RTK Support: Enables centimeter-level positioning via network RTK or communication with a base station. When a fixed solution (Fix) is obtained, horizontal errors typically fall within about 1–3 cm.

• NTRIP Connectivity: Built-in NTRIP client allows reception of correction data over the Internet. You can connect to public electronic reference stations or private correction services (VRS, etc.) without deploying your own base station.

• Coordinate Transformation: Automatically converts WGS-84 latitude/longitude from GNSS into your site’s coordinate system (e.g., Japan’s plane rectangular coordinates or a custom local grid), reducing post-processing work by delivering site-ready coordinates in real time.

• Data Export: Exports measured point coordinates in formats such as CSV or KML, enabling use in CAD drawings, GIS software, or Google Earth. Some apps also support Shapefile or DXF output.

• Positioning Status Display: Shows real-time satellite count, RTK Fix/Float status, and estimated accuracy (HRMS/VRMS), so you can monitor and ensure precision directly on site.

• Other Features: Depending on the app, you may find track logging for continuous positioning, averaged positioning modes, photo capture with embedded location data, AR-guided stakeout, and more.

By leveraging GNSS surveying apps in this way, your smartphone can serve as a high-precision GPS tool, greatly streamlining surveying and stakeout operations in the civil engineering and construction sectors.

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Recommended RTK-Compatible GNSS Surveying Apps
We’ve handpicked five RTK-compatible GNSS surveying smartphone apps for field use and compared their key features. Select the app that best suits your application needs and budget.

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LRTK Official App (High-Precision RTK-GNSS Positioning)
Our LRTK Official App is the dedicated surveying application designed to work seamlessly with our compact RTK-GNSS receivers in the LRTK series. With this app, your iPhone or Android device becomes a pocket-sized survey instrument. By pairing it via Bluetooth with an LRTK device (such as the LRTK Phone or Pro2) and configuring network RTK (NTRIP client) settings, you can achieve centimeter-level positioning. The app delivers fast, stable RTK fixed solutions, making the difference from standalone GNSS fixes immediately apparent.

Designed with field users in mind, the LRTK app lets you receive correction data and start positioning with a single tap, and it automatically converts and displays coordinates in your chosen plane-rectangular system. You can flexibly switch between single-point and continuous measurement modes, and use the averaging function to further improve accuracy. Captured points are plotted instantly on a cloud map, allowing you to intuitively visualize spatial relationships right on your smartphone screen.

Moreover, the app is packed with advanced features, including photo-based positioning—which captures an image and records its exact location and orientation—a LiDAR scan mode for acquiring 3D terrain point clouds, and an AR navigation feature that guides you to target points on site. Despite this rich functionality, the UI/UX remains simple and is optimized to provide a seamless workflow from starting a survey to sharing your data. The app itself is freely available even to users without LRTK hardware, making it an exceptionally well-balanced, RTK-enabled high-precision GPS solution.

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Free RTK-Compatible Apps (Feature Limitations)
If you want to try RTK without spending a budget, there are several RTK-enabled apps available at no cost. A representative example is SW Maps for Android. SW Maps is primarily a geospatial data‐logging app, but when paired with an external RTK-GNSS receiver, it supports centimeter-level positioning. Despite being free, it includes a built-in NTRIP client for fetching correction data over the Internet and performing high-precision positioning. The app also lets you attach photos and notes to surveyed points and use topographic maps or aerial imagery as GIS base layers, enabling basic surveying and data-recording tasks at minimal cost.

However, there are some caveats with free apps. First, official support is limited, and bug fixes or updates may occur irregularly. Also, the range of supported coordinate systems can be narrow (e.g., only WGS-84 latitude/longitude or UTM), so handling Japan’s unique grid systems may require additional workarounds. Many apps offer interfaces and manuals only in English, meaning initial setup may demand prior GPS or RTK knowledge. Still, the ability to try smartphone RTK apps at no cost is a major advantage, making them a compelling choice for in-house testing or personal learning.

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Paid / Subscription-Based Apps (Balancing Price and Features)
If you require advanced functionality and robust support, you should consider paid surveying apps. These come in two models: a perpetual license (one‐time purchase with no further fees) and a subscription plan (monthly or annual fees for always having the latest version).

For example, Mobile Topographer Pro for Android is a perpetual-license surveying app that can be purchased for just a few thousand yen and includes coordinate‐conversion and surveying‐calculation functions. While it does require an upfront cost, its appeal lies in having no ongoing fees thereafter.

On the other hand, some apps are offered via subscription, such as Esri’s ArcGIS Field Maps and Trimble’s Trimble Catalyst. ArcGIS Field Maps is an enterprise GIS data‐collection app: by paying the ArcGIS Online subscription, you gain access to advanced mapping and GNSS‐integration features. Trimble Catalyst provides RTK services with a dedicated antenna on a monthly subscription basis, allowing you to subscribe only for the periods you need and achieve centimeter‐level accuracy.

Paid/Subscription-Based Apps are attractive for their rich feature sets and reliability that justify their cost. Most offer added value beyond free apps—such as NTRIP connectivity, support for multiple coordinate systems, data management and sharing tools, and dedicated customer support. Their UIs are polished and optimized for field use. Subscription models also ensure you always have the latest version and rapid compatibility with OS updates. However, the breadth of features can mean a learning curve to master. It’s best to weigh cost against functionality and select the model that aligns with your organization’s needs.

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Features and Usage of the LRTK App
We’ve compared various GNSS surveying apps up to this point; now let’s turn our attention to the LRTK app and take a closer look at its key features and how to use it. When combined with our in-house hardware, the LRTK app delivers a dramatic boost in both positioning accuracy and ease of use.

The LRTK Phone device attaches to your smartphone—simply snap the ultra-compact RTK receiver onto the back of an iPhone or iPad, and your phone instantly becomes a centimeter-accuracy surveying instrument. Weighing just 125 g and featuring a slim profile, it’s highly portable, and its ready-to-use convenience lets you pull it out and start high-precision positioning whenever you need it.

Improved Positioning Accuracy: With the combination of the LRTK app and device, you can achieve precise positioning both outdoors and indoors. In addition to receiving signals from GNSS satellites, it also supports centimeter-class augmentation signals (CLAS) from Japan’s QZSS “Michibiki,” maintaining high accuracy even in areas outside cellular coverage.

For example, during infrastructure inspections in mountainous areas or underground spaces, the ability to position without relying on a cellular network provides significant peace of mind on site. Of course, when you are within network coverage, you can connect via NTRIP to local electronic reference-station networks and maintain a stable RTK fixed solution at all times. By using our proprietary averaging function, you can statistically correct positioning values even in environments where obtaining a fixed solution is difficult, further improving accuracy. In fact, we have observed cases where standalone fixes with errors of approximately 12 mm were reduced to 8 mm through averaging.

Differences and Advantages Compared to Other Apps: What sets the LRTK app apart is its ability to offer a rich set of features through an intuitive, easy-to-use interface.

For example, when you photograph a surveyed point, the app automatically tags the image with high-precision coordinates and the camera’s orientation. Later, simply reviewing the photo lets you view the capture location on a map and easily cross-reference past project records. In AR mode, you can overlay the direction of previously measured points onto your phone’s camera viewfinder, making it simple to locate those points on site. This enables a single operator to efficiently perform tasks such as pinpointing buried utilities or staking out design coordinates. Furthermore, on LiDAR-equipped iPhones or iPads, you can scan surrounding terrain and structures to capture 3D point-cloud data. All captured point clouds and images can be uploaded to the cloud for storage and sharing, seamlessly integrating into post-processing workflows for detailed analysis and team collaboration back at the office.

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How to Integrate with LRTK Devices: Setting up and connecting the LRTK app is straightforward. First, mount the dedicated device (e.g., LRTK Phone or LRTK Pro2) onto your smartphone and pair via Bluetooth. Then, simply select the device in the app and choose your correction source—either NTRIP over the Internet or Michibiki CLAS—and you’re ready to survey.

While measuring, the device continuously streams high-precision coordinates to your phone, which are displayed in real time on the app. The app also supports tilt compensation: even if you must survey at an angle to avoid obstacles, it automatically corrects the coordinates to the point directly beneath the pole’s tip.

The LRTK app is available for iOS, so you can choose the version that matches your field device. All collected data can sync with the LRTK Cloud, allowing you to review survey points and photos on a web map from your office PC and seamlessly incorporate them into daily reports.

In this way, the LRTK app, when paired with its dedicated device, serves as an integrated solution that enables anyone to achieve high-precision positioning with ease.

Its all-in-one capabilities—covering positioning, point-cloud capture, stakeout, photo documentation, and AR navigation on a single unit—dramatically enhance both productivity and accuracy in the field. From general-contractor site management to infrastructure inspection and disaster surveying, the LRTK system is being adopted across a wide range of applications, turning the vision of “one survey-capable smartphone per person” into reality.