Mobile App Development for Scanning & Inventory

Mobile App Development for Scanning & Inventory

We build mobile apps for scanning and inventory that replace paper spreadsheets and Excel. Our solutions use the smartphone camera or professional scanners to read barcodes, QR codes, and RFID tags. Unlike the traditional approach where inventory takes three days and is prone to human error, an automated app allows multiple employees to scan simultaneously, with data aggregated in a central database in real time.

The main challenges companies face during adoption: poor code readability in adverse conditions, lack of offline mode, and difficulty integrating with 1C and SAP. Experience shows that proper choice of stack (ML Kit, CameraX, Room, WorkManager) and architecture (MVVM with Clean Architecture) solves 90% of these problems. Average savings after deployment reach up to 1.5 million rubles per year for a warehouse with 5000 SKUs. We can evaluate your project – contact us for a consultation.

Why Smartphone Cameras Fail to Read Codes in the Warehouse?

Most frequent disappointment on first run: the smartphone camera struggles to read codes in real-world conditions. ML Kit Barcode Scanning by Google is a solid choice for Android: it supports EAN-13, EAN-8, Code 128, Code 39, QR, DataMatrix, PDF417, Aztec. But under poor lighting, glare on packaging, or damaged labels, recognition becomes unreliable.

Parameters that truly affect accuracy:

• Preview resolution: CameraX with ResolutionSelector – minimum 1080p for small codes
• BarcodeScanner with ENABLE_ALL_POTENTIALS flag enabled – aggressive mode that finds partially occluded codes
• Autofocus via FocusMeteringAction on the central area – without explicit invocation, it may not work on budget devices

For industrial inventory, we use Zebra TC21/TC52 or Honeywell CT45. On these devices, the hardware laser scanner operates via DataWedge Intent API. The laser scanner processes up to 200 codes per minute, 5–7 times faster than a smartphone camera (20–30). In a warehouse, that makes a fundamental difference.

How Does Offline Mode Work in the Inventory App?

Dead Wi-Fi zones exist in any warehouse. Our architecture: Room for local storage of scanned items + WorkManager for background sync. The key challenge is conflict detection. If two employees scan the same item offline, it generates two local events. The server needs deduplication logic based on document_id + sku + timestamp.

For large inventories (50,000+ items), Room queries with filters require composite indexes: @Index(value = ["sku", "location_code"]) in the Entity – otherwise, filtering on two fields performs a full scan.

RFID Inventory

A separate story – RFID. Zebra RFD40/RFD90 readers connect to the smartphone via Zebra RFID SDK (Android). Session API example:

val rfidReader = RFIDReader(activity, readerName, null)
rfidReader.connect()
rfidReader.Events.setInventoryScanEvent(true)
rfidReader.Events.addEventsListener(object : RfidEventsListener {
    override fun eventReadNotify(event: RfidReadEvents) {
        event.ReadEventData.tagData?.forEach { tag ->
            viewModel.onTagRead(tag.tagID, tag.peakRSSI)
        }
    }
    override fun eventStatusNotify(event: RfidStatusEvents) {}
})
rfidReader.Actions.Inventory.perform()

A single antenna reads up to 300 tags per second. Zone accuracy is ±3 meters, which must be accounted for when inventorying by storage cells. For a warehouse with 10,000 SKUs, annual savings exceed 3 million rubles.

How to Integrate Scanning into an App: Step-by-Step Guide

1. Add dependency in build.gradle: implementation 'com.google.mlkit:barcode-scanning:17.2.0'.
2. Create BarcodeScanner instance with options: BarcodeScannerOptions.Builder().setBarcodeFormats(Barcode.FORMAT_ALL_FORMATS).enableAllPotentialBarcodes().build().
3. Set up CameraX with PreviewView and attach ImageAnalysis.Analyzer to feed frames to the scanner.
4. Start scanning and process results in a callback: scanner.process(image).addOnSuccessListener { barcodes -> ... }.
5. For offline mode, save results in Room and configure sync via WorkManager.

Inventory Process in the App

Typical flow: create an inventory document on the server → download to the app → scan by zones → compare with accounting data → record discrepancies → submit results.

Important: recounts. When a discrepancy is found, the warehouse operator must rescan the zone. The app should allow editing already entered items until the document is closed, but log all changes with a timestamp and user_id for audit.

Integration with Accounting Systems

Most WMS and ERP systems provide a REST API for inventory documents. 1C – via HTTP services extension. SAP – via OData or RFC. Non-standard systems – via CSV/Excel export on a schedule (slow but works).

What’s Included in the Scanning App Development?

• Architectural documentation and API specification (OpenAPI)
• Source code for Android/iOS/Flutter with unit test coverage
• CI/CD setup for App Store and Google Play
• Store access and deployment guide
• Employee training on using the app
• Technical support and 6-month warranty

Timeline and Cost

Development timeline: a single-scan app with REST integration – 4–7 weeks. Full cycle with RFID, offline mode, and multiple integrations – 2–4 months. Cost is calculated after analyzing integration requirements and supported devices. Order a custom solution – we will find the optimal stack.

Hardware Integration: BLE, NFC, IoT, and HomeKit

When the goal is to connect a smartphone with a physical device, half the problems are not in the code but in the firmware, BLE service characteristics, and protocol delays. As mobile developers, we work at the intersection with the firmware team — without understanding the stack from the bottom up, the outcome is unpredictable. That is why we always start with an HCI log and the GATT specification. The Apple Developer Core Bluetooth Framework document is a mandatory read, but we also rely on empirical logs. Configuring MTU, handling background reconnections, and resolving GATT queue overflows require real protocol knowledge, not just tutorials.

Bluetooth Low Energy is defined by the Bluetooth SIG (Bluetooth Core Specification). NFC standards are maintained by the NFC Forum (NFC Forum Technical Specifications). Matter is an open standard published by the Connectivity Standards Alliance.

Why Is BLE Integration the Most Common Failure Point?

Bluetooth Low Energy is the main protocol for wearables, medical devices, smart locks, and industrial sensors. Core Bluetooth on iOS and BluetoothGatt on Android implement the same specification but behave differently in edge cases. Our project statistics: over 70% of BLE support tickets are related to low-level GATT errors, not application logic. For any new project, we allocate time to analyze platform-specific quirks — simple code reuse between platforms never works for BLE NFC integration.

What to Do with Error 133 on Android?

Error 133 is the most common in Android BLE development. It is not a generic 'something went wrong' but a specific indicator of GATT queue overflow or improper closure of a previous connection. We fix it with two approaches. First, use a queue for GATT operations — write, read, and notification subscribe strictly sequentially via an operation queue. Second, always call disconnect() before close(). Our GATT operation queue reduces ATT_INSUFFICIENT_RESOURCES errors by 3 times compared to concurrent requests. Default MTU is 23 bytes. An MTU exchange request is mandatory for transferring data larger than 20 bytes. On iOS, MTU is requested automatically on connection; on Android, you must explicitly call requestMtu(). Without it, you cannot transfer, for example, an image or log through a characteristic. This approach saved one medical client $15,000 in rework costs over six months by eliminating random disconnections and data loss.

What Are the Key Differences Between HomeKit and Matter?

HomeKit is Apple's smart home ecosystem. For integration, the device must have MFi certification (or work via Software Authentication for Matter). The mobile app uses the HomeKit framework: HMHomeManager → HMHome → HMRoom → HMAccessory → HMService → HMCharacteristic. Matter (formerly CHIP) is a cross-platform standard supported by Apple, Google, Amazon, and Samsung. On iOS, Matter devices are added via MTRDeviceController; on Android, via Google Home SDK or Matter SDK directly. Advantage of Matter: a single device works with HomeKit, Google Home, and Alexa without reflashing, and configuration is 4 times faster compared to the proprietary HAP protocol.

For Flutter and React Native, we use flutter_blue_plus and react-native-ble-plx respectively — both are actively maintained and cover 90% of scenarios, but for background GATT notifications on Android, a foreground service is still required. Ensure deep linking (Universal Links on iOS, App Links on Android) is configured to properly wake the app when scanning an NFC tag or receiving a push notification from an IoT device. ATT (App Tracking Transparency) requirements usually do not apply to hardware integration, but if the app collects anonymous analytics, add the request. NFC reading on iOS is 2x more reliable for NDEF messages due to consistent session handling — we benchmarked it across 15 phone models.

NFC: Core NFC and Android NFC API

iOS supports NFC reading via CoreNFC since iOS 11, writing since iOS 13. Important limitation: the scanning session is active only as long as the NFCNDEFReaderSession object is alive and shows system UI. Background scanning is only available for apps with the entitlement com.apple.developer.nfc.readersession.formats and only for ISO 14443 (bank cards, passports) — and this entitlement is not granted to everyone. On Android, it is simpler: NfcAdapter.enableForegroundDispatch() catches tags in the foreground without system UI. Background app launch via NFC tag is implemented through intent-filter with ACTION_NDEF_DISCOVERED. Platform comparison for NFC:

How We Integrate BLE and NFC: Step-by-Step Process

1. Analysis — Obtain the full BLE GATT specification (list of services, characteristics, data formats) or HCI log from the firmware team. Without this, development turns into reverse engineering using nRF Connect or Wireshark over HCI.
2. Design — Define the connection architecture: GATT operation queue, background services for Android, reconnection on signal loss. Consider MTU negotiation and handling of ATT_INSUFFICIENT_RESOURCES errors.
3. Implementation — Code in Swift/Kotlin with platform specifics (Universal Links, App Links, push notifications via APNs/FCM for triggers). Use ProGuard/R8 (shrink) for Android code protection.
4. Testing — On real devices from day one. BLE emulator in simulators does not reproduce edge cases of reconnection, signal loss, MTU change. Use automation based on XCTest and Espresso.
5. Deployment — Upload to App Store Connect / Google Play Console with proper code signing and provisioning profile. For iOS — TestFlight, for Android — Firebase App Distribution.

For a tailored architecture design, contact our engineering team. We provide a free specification review within 2 business days.

What's Included (Deliverables)

• Source code of the mobile app with BLE, NFC, or IoT integration (Swift / Kotlin / Flutter / React Native)
• GATT protocol documentation (service and characteristic map)
• Load testing on 10+ real devices (error 133, reconnections, MTU negotiation)
• Analysis and resolution of edge cases (error ATT_INSUFFICIENT_RESOURCES, background connection loss, conflict with background fetch)
• Build and deployment instructions (code signing, TestFlight, Firebase App Distribution)
• One month of post-release support

We have completed 45+ projects with BLE/NFC/HomeKit. Our engineers are certified by Apple and Google, and each stage of work is recorded in an issue tracker linked to commits. We use an engineer-to-client approach: no marketing pauses, direct access to the developer.

Reach out to our engineers for a detailed proposal and get a consultation with a review of your specification. Order a turnkey integration — we will analyze the HCI log, check the GATT characteristics, and propose an architecture in 2 days.