Service · App development

Custom geo (geographic) app development.

A custom app for everything involving location, maps and spatial data. Field surveys, asset tracking, ecological research, indoor positioning, smart city and real-time fleet management, built on a mapping stack that suits your data and your sector. Native for iOS and Android, with offline tiles and GIS integrations.

Mapbox & LeafletPDOK & ESRIOffline tilesGeoJSON & shapefile

A geo app is more than a map with points.

A geo app, in short, links your work process to the place where it happens. For a field surveyor, that means a form that attaches to the polygon of the plot they are standing on. For a fleet coordinator, it means 280 vehicles moving in real time across a map, with geofences around warehouses and customers. For a municipal inspector, it means an enforcement report that appears as a GPS point on the PDOK public-space layer. In each case the map is not decoration but the heart of the work process.

Most off-the-shelf industry packages have a blind spot here. A standard CRM or ERP is concerned with customers and hours, not coordinates, projections or indoor routing. Anyone who tries to force a geo workflow into a generic package ends up with separate mobile forms plus a GIS file that is converted by hand at the end of the day. Not because it cannot be done, but because spatial data has a fundamentally different structure from tables of rows and fields.

We build custom geo apps for organisations for whom location is essential to the work process itself, not as reporting after the fact but as guidance during the work. That means a stack in which Mapbox, Leaflet, ESRI or PDOK runs directly inside the app, integrations with your existing GIS or CAD environment, and an offline mode that genuinely works offline. For field surveys in nature reserves without coverage, for inspection rounds in an underground car park, and for archaeological work where uploading to a server is simply not an option.

Geo often overlaps with other disciplines within app development: a field service app soon needs a map layer, logistics planning requires routing, and an asset management system relies on location. We carry these threads through so the mapping layer doesn't become a separate module, but is woven into the entire application. For the overlap with inspection and engineer workflows, see our page on field service apps, as many geo projects are effectively an extension of those.

Three common forms.

Which approach suits your organisation depends on who works with the map, whether the data is generated in-house or out in the field, and which mapping stack you already have in place. In the first conversation, we advise on which option will deliver the most value.

Compact project · fixed sprint budget

Field survey and terrain recording app

A mobile app that lets ecologists, archaeologists, surveyors or vegetation recorders capture points, lines and polygons in the field, with photo attachments and forms that vary by object type. It works offline on a pre-downloaded map area, syncs as soon as the network returns, and exports directly to GeoJSON, shapefile or a GIS platform such as QGIS or ArcGIS Online. Often with automatic GPS accuracy determination and the option to achieve sub-metre precision using an external GNSS receiver.

Offline tilesGeoJSON exportGNSS integrationQGIS publication
Mid-sized project · fixed sprint budget

Asset tracking and fleet app

For logistics, recycling, gritting, refuse collection, technical maintenance or construction plant: a live map of all your vehicles, machines or containers, with geofences around warehouses, customers and project sites. Push notifications when an asset enters or leaves a geofence, automatic trip logging, mileage reporting and integration with your fleet or ERP system. For the transport side of this, we often draw on the approach from our transport software work, as geo and planning form one whole there.

Real-time trackingGeofencingMapbox & MaptilerTrip logging
Larger project · fixed sprint budget

Smart city and public domain app

For municipalities, water boards, environmental services and provinces: an app that links public space reports, asset inspections or resident feedback to the official map layers of PDOK, BAG, BRO and the Kadaster. It includes an accessible public version for residents and a professional section for inspectors. INSPIRE-compliant where publications are concerned, with an audit log for enforcement procedures, and interoperable with your GIS environment. This overlaps with our experience from software for municipalities.

PDOK & BAGINSPIRE-compliantAudit logPublic version

What a geo app can do as standard.

The core functional layers that recur in almost every geo project, whether you're thinking of field research, asset tracking or smart city. We adapt this foundation each time to your sector, your data and your existing GIS environment.

  • Multi-stack mapping engineA mapping layer that works with Mapbox GL, Maptiler, Leaflet on top of OpenStreetMap, Google Maps or ESRI ArcGIS, depending on your licences, audience and map style. We choose together what fits and build the app so the underlying tile providers can be swapped out later without a redesign.
  • Reading vector and raster dataNative support for GeoJSON, shapefile, KML, GeoTIFF, GeoPackage and CSV files with coordinates. Large datasets are tiled client-side and only the relevant features are rendered, so even thousands of polygons run smoothly on a phone.
  • Offline tiles and offline dataBefore heading out, the field worker selects a work area and downloads tiles and features to the device. In the field the app then works fully offline, even deep inside a nature reserve, in a warehouse or out on the Wadden Sea. Synchronisation happens automatically once a connection is restored, with conflict resolution for objects that several field workers have edited at the same time.
  • GPS accuracy and GNSS supportFor most use cases the device's built-in GPS chip is sufficient, using CoreLocation on iOS and the Fused Location Provider on Android. For sub-metre or centimetre precision we connect external GNSS receivers over Bluetooth (Trimble, Emlid, Septentrio), with RTK correction via an NTRIP stream.
  • Routing and navigationRouting on public roads via the Mapbox Directions API, Google Directions or OSRM, and off-road routing for terrain without roads. For fleet workflows with multiple stops, the app generates an optimised sequence, with estimated arrival times and recalculation in the event of traffic jams or road closures.
  • Geofencing and triggersDraw polygons around warehouses, customer sites, project areas or nature zones. The app responds when a user or asset enters or leaves them, by suggesting a form, sending a notification to the office, or starting time registration. Works in the background, even when the app is not open.
  • Indoor positioningFor situations without GPS coverage: indoor positioning based on Bluetooth beacons, Wi-Fi fingerprinting or a BIM model (IFC) of the building. Suitable for warehouse picking, hospital wayfinding or inspections in tunnels and car parks.
  • AR overlayUsing ARKit (iOS) or ARCore (Android), we can show underground cables, pipes, archaeological layers or planned construction over the real world through the camera. Particularly useful for excavation crews, designers and public-facing applications in the built environment.
  • Integration with your GIS environmentTwo-way integration with QGIS, ArcGIS Online, GeoServer or your own PostGIS database. What is recorded in the field appears straight away on your office map, and what the GIS analyst draws lands directly as a layer on the devices in the field.
  • GDPR-compliant handling of location dataA person's location is a special category of personal data under the GDPR. We build consent flows, data minimisation and retention periods directly into the app, with an audit log for when location is or is not collected. This also applies to fleet flows involving vehicles assigned to individuals, and to public apps where residents share their location.
  • Maintenance contract (optional)Ongoing maintenance, OS updates, security patches and further development for a fixed monthly fee. Tile licences, GNSS firmware updates and GDPR reviews can be included.

When a geo app is the right choice.

Not every workflow involving a map needs its own geo app — sometimes a dashboard in QGIS or a feature layer in ArcGIS Online is enough. Six signals where custom geo software really pays off.

Fieldwork

Data is created outside the office

Your inspectors, ecologists or site supervisors record on the spot the facts that later end up in a report or analysis. The less they note in the field and the more they retype afterwards, the more noise creeps into the final report — and the longer the turnaround time. A geo app captures it at the point of observation.

Offline

No or poor network coverage in the working area

A nature reserve, an underground utility network, a storage shed, a remote worksite — anywhere mobile coverage is patchy or absent, a browser-based GIS tool fails. A native app, with pre-downloaded tiles and local storage, keeps working.

Volume

Many objects or many fields

A ranger measuring thirty tree trunks a day, a harbour master logging a hundred containers an hour, an inspector carrying out six inspections in a morning — in those cases every second per record adds up. A dedicated workflow is far quicker than a generic "add point" button in an off-the-shelf package.

Compliance

INSPIRE or audit log required

Public-sector work calls for a traceable chain: who recorded what, at what accuracy, and is it still valid? INSPIRE-compliant metadata, an immutable audit log and feature versioning are not standard in every package — custom development solves all of this in one go.

Integration

GIS platform is not the single source

Your map data lives in ArcGIS, but your core data sits in an ERP, a BIM server or a line-of-business application. Standard mobile GIS clients only connect to their own platform. A custom app pulls features from several sources and presents them as one layered map.

Branding

Public or partner experience matters

A citizen reporting app, a walking tour, a property search app or a tour of a nature reserve — when end users are not GIS professionals, the interface needs to match your brand and avoid jargon. A white-labelled version of a GIS platform rarely feels like your own brand.

Not yet sure about a large project?

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How a geo-app project runs.

1

Introduction and data review

A conversation in which we map out your working process and look at the data you already have: which map layers, in which projection, with what metadata. We review your existing GIS environment, tile licences and any PDOK or ESRI subscriptions, and advise what can be reused and where new layers are needed.

2

Field research and stack selection

Depending on your use case, we spend a day accompanying a field survey, observing a fleet coordinator at work or shadowing an inspector. Based on that, we select the mapping stack (Mapbox, Maptiler, Leaflet, ESRI or a combination), the cross-platform approach (Flutter, React Native or native iOS and Android) and the backend architecture. We test the first wireframes with two or three end users before we start building.

3

Building in sprints

Each sprint we deliver a working version on your own devices. We begin with the mapping engine plus one primary flow (for example, a field form attached to a geometry), so you can test at real locations as early as possible. We then build offline tiles, integrations and the related role-based flows. You test along the way, field users test too, and we adjust continuously.

4

GIS integration and rollout

We test the integrations with your GIS platform or database first in a staging environment with representative data, then with a pilot group of a few field workers. We check projections, transformations between RD-New and WGS84, and behaviour when network connections drop. This includes training sessions for planners and GIS analysts, plus a short instruction video for end users.

5

Operations and ongoing development

After go-live we provide support with monitoring, OS updates for iOS and Android, security patches, GNSS firmware checks and further development. Many geo-apps grow organically — new map layers, new regions, a second industry application — and a maintenance contract keeps that running smoothly without starting a new project each time.

Frequently asked questions.

The questions clients ask when they are considering a geo-app.

Which mapping stack do you usually choose?
That depends on the use case. For consumer and public-facing apps we often work with Mapbox GL or Maptiler, thanks to their attractive vector styling and reasonable licence costs. For public-sector projects we usually choose Leaflet on top of OpenStreetMap, or a combination with PDOK tiles, because that is licence-free and interoperable. For organisations that already invest heavily in ESRI, we align with ArcGIS Online or ArcGIS Enterprise. We use Google Maps where recognisability matters more than customisation. We always advise based on your data, target audience and existing contracts, not on what we happen to be familiar with.
How accurate is the location in the app?
With the standard GPS chip in modern smartphones, you typically get three to five metres of accuracy in the open air, and slightly less in urban areas. For field surveys, archaeology or cable and pipe work that is sometimes not enough, so we connect external GNSS receivers such as the Trimble Catalyst, Emlid Reach or a Septentrio Mosaic over Bluetooth. With RTK correction via an NTRIP stream, you then achieve centimetre precision. The app automatically falls back to the built-in GPS if the external receiver is unavailable.
Does the app really work offline in an area without a network?
Yes, that is a core requirement for most of the geo apps we build. We download tiles and feature data to the device in advance, store all work orders, photos and measurements locally in a SQLite or MMKV store, and synchronise via a queue once the network is back. Conflict resolution for objects edited by several field workers at the same time is built into the design by default. We test this every sprint in aeroplane mode and on poor 4G, not just on a fast Wi-Fi connection in the office.
Can you integrate with our GIS environment?
In practice, almost always. For ESRI: ArcGIS Online via REST services or ArcGIS Enterprise. For open-source stacks: GeoServer with WMS, WFS or WMTS, or a direct PostGIS database. For QGIS publications: an intermediate step via a WFS feed or an exported GeoPackage. For PDOK data: the open WMS and WFS services. We set up two-way integration where that makes sense, so field captures land in your office GIS automatically and vice versa.
What about GDPR when it comes to people's location data?
A person's location falls under special category personal data under the GDPR, particularly when it is collected continuously or in real time. We build consent flows, data minimisation and retention periods directly into the app, with an audit log recording when and why location is collected. For fleet applications involving personally assigned vehicles, we work with works council agreements and privacy-by-design principles. For projects involving the location of patients, pupils or residents, we carry out a DPIA as standard. We work with your privacy officer or data protection officer to clarify the legal boundaries.
How do you combine a geo-app with AI or image recognition?
Organisations increasingly want a photo taken in the field to be automatically categorised or analysed. For example: an ecologist photographs a plant and immediately gets the species back; an inspector records waste and has the type detected automatically; a property surveyor photographs damage and receives an initial assessment. We build this as a separate AI layer on top of the geo-app, with models running on-device or in the cloud depending on privacy requirements and data volume. For our approach and capabilities, see our page on AI development.
What is INSPIRE and do we need to comply with it?
INSPIRE is a European directive that obliges public authorities to publish certain spatial datasets in a standardised format and with standardised metadata. If you are a municipality, water board, province or environmental service working with public spatial data, this usually applies to you. We make sure your app's data export produces the correct GML or GeoJSON formats, with metadata in the ISO 19115 format. For private parties, INSPIRE usually does not apply, but interoperability with PDOK datasets is often still desirable.
Can you do indoor positioning without GPS?
Yes. We place Bluetooth beacons (from providers such as Estimote or Kontakt.io) at fixed positions, and triangulation gives a position accurate to within a few metres. For larger buildings we use Wi-Fi fingerprinting on top of existing access points. For BIM-driven routing we load an IFC model into the app, so users can navigate through a 3D representation of the building. Indoor positioning works best for organisations with a fixed physical infrastructure, such as warehouses, hospitals, stadiums and car parks.
Native or cross-platform?
For geo apps we typically choose Flutter or React Native, because the mapping libraries (Mapbox GL Native, MapLibre, Leaflet via a webview) work similarly on both platforms and you keep a single codebase. For projects with very demanding graphical requirements or highly specific hardware integrations, such as deep integration with an external GNSS receiver via a proprietary SDK, we sometimes opt for native iOS (Swift with MapKit and CoreLocation) and native Android (Kotlin with the Maps SDK). We discuss during discovery what suits your requirements and existing engineering capacity.
Who manages the tile licences and hosting costs?
This forms part of the management contract if you take one out. Mapbox, Maptiler and Google Maps use a usage-based model (per map load or per tile request), while ESRI works with named users. We monitor usage, scale the plan up or down, and provide you with monthly insight. For public-sector projects we use PDOK tiles wherever possible, as these are licence-free, with a commercial provider as a fallback for specific styles or regions.
Do you also work alongside our own GIS analysts or developers?
Yes, that is more the rule than the exception with geo projects. Many clients have a GIS team that handles the data layer and analyses, while we build the mobile layer and, where needed, the intermediate APIs. We work in the same Git repository, align with your projections and data models, and pair-program where that speeds up knowledge transfer. At the end of the engagement your own team can maintain the codebase fully independently, with no lock-in to us as a supplier.

Talk to us about your geo app.

A free, no-obligation half-hour introductory call. We listen to your working process, look along with you at the map layers and data you already have, and give direction you can use, including when the advice is to go further first with QGIS, ArcGIS Online or a PDOK viewer before custom work is worthwhile. For related topics, see our broader app development service, our page on field service apps, our experience with transport software for asset tracking, our projects in software for municipalities, and the application of AI development to geo data.

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