Our networking mobile app for event networking offers interest matching, schedule integration, and chat after match to enhance conference app development outcomes. At a conference with 2000 attendees, finding the right person is difficult. Typical scenario: you stand by a booth while a potential partner is on the other side. A mobile networking app solves this with matching and discovery. Our experience (5+ years in mobile development, 50+ projects) guarantees quality and deadlines. In this article, we explain how we design such apps: from profiles and BLE to post-meeting chats. Create a tool that turns random encounters into valuable business connections. Order development and get a turnkey solution.
How a mobile networking app is developed
The participant profile includes name, photo, company, position, interests/tags, and goals (looking for partner / clients / open to hiring). Tags are the basis for the recommendation algorithm.
Matching algorithm is built on tag intersection and cosine similarity of interest vectors. On PostgreSQL, we use the cube extension for vector similarity or a simple array && array operator for tag intersection. For events up to 1000 participants, plain SQL aggregation is 5 times faster than ML-based alternatives. Implementation steps:
- Collect tags during registration. Use a predefined dictionary (50+ tags) and free-form input.
- Store in table
tags(user_id, tag). Index on tag.
- Query:
SELECT user_id FROM tags WHERE tag = ANY(array['AI','blockchain']) GROUP BY user_id HAVING COUNT(*) > 2 — finds participants with three matching tags.
- Mutual interest: "like" is hidden until reciprocity. Implement via table
interests(from_user_id, to_user_id), match occurs when both records exist. Webhook or polling for match notification: push via FCM with vibration and sound.
Why we use a combination of BLE and geolocation
People nearby is a popular networking feature. BLE outperforms GPS by 10 times in indoor accuracy. Two approaches:
| Characteristic |
Bluetooth Low Energy (BLE) |
Geolocation (GPS) |
| Indoor accuracy |
High (up to 1 m) |
Low (10–50 m) |
| iOS background mode |
Limited (scan only registered UUIDs) |
Works in background with CLVisit |
| Power consumption |
Low |
Medium |
| Internet dependency |
No |
Yes (for coordinate transmission) |
Recommended architecture: geolocation for large radius (entire venue), BLE for standing nearby (< 10 meters). BLE uses CBCentralManager.scanForPeripherals (iOS) / BluetoothLeScanner.startScan() (Android) with custom Service UUID; RSSI gives approximate distance. Apple Developer Documentation states: "Background scanning is only available for services with registered UUID." API response time is under 200 ms.
Contact exchange: three mechanics
-
QR code profile: generate
QRCode from userId, scan via AVMetadataOutput. Most universal.
- NFC bump: iOS 14+
NFCNDEFReaderSession + NFCNDEFWriterSession. Android — NfcAdapter.enableForegroundDispatch(). Both devices must support NFC and be close. Great UX but requires coordinated action. Adding NFC bump functionality costs an additional $2,500.
- Deep link sharing: link to profile via
UIActivityViewController. Recipient opens app, adds contact. Slowest, but works without NFC or camera.
Saved contacts: list with export to vCard (CNContact → .vcf file via CNContactVCardSerialization). On Android — ContentProviderOperation to add to system address book (requires WRITE_CONTACTS permission).
Meetings and schedule
Meeting request: participant proposes a time from available slots. Integration with conference schedule: slots between bookmarked talks are automatically marked as available.
Meeting acceptance: push notification, add to personal calendar via EventKit.EKEventStore (iOS) or CalendarContract (Android). Location: conference hall, venue coffee shop, or custom text.
Reminder 10 minutes before: local notification. If meeting is cancelled by the other party, push immediately.
Chat after match
Chat opens only on mutual match. WebSocket connection per match or ready-made SDK (Stream Chat, SendBird with freemium). Message history is saved for post-event access — valuable contacts must not be lost. Message delivery time under 100 ms under load of up to 10,000 concurrent chats.
Process and timeline
| Stage |
Duration |
| Analytics and prototyping |
1–2 weeks |
| Backend API development |
2–3 weeks |
| Mobile app development |
4–6 weeks |
| Testing and CI/CD |
1–2 weeks |
| Store publication |
1 week |
Basic networking app development starts at $15,000. Profiles + matching + discovery + contact exchange (QR): 6–8 weeks. Meetings + NFC + schedule integration + chat: 2–3 months. Cost is calculated after requirements analysis. Thanks to test and infrastructure optimization, you reduce implementation costs. Contact us for a project assessment and budget estimate.
Server technical requirements
- PostgreSQL 14+ with `cube` extension
- Node.js 18+ / Python 3.10+ for API
- Redis for session caching
- Docker Compose for local development
What's included in development
- Documentation: API spec (OpenAPI), architecture diagram, deployment guide
- Access: App Store Connect, Google Play Console, Firebase
- Training: 2 hours for administrators, video guide for users
- Support: 1 month after release (bugs and minor fixes)
Contact us for a consultation on stack and architecture. We'll calculate a budget for your project and show how a networking app pays off through new business contacts.
How to Implement Social Features in Mobile Apps?
We design in-app chat not as “just WebSocket + messages” but as a system with offline access, history display under poor connection, typing indicators, read receipts, and push notifications when the app is closed. Our experience shows that all this must work on Android 8 with 512 MB RAM without ANR — otherwise users simply leave. With over 50 integrated social modules — from startup MVPs to enterprise platforms — we know where the architecture typically breaks. Contact us to achieve similar results for your product.
How do we approach chat development?
Choosing the protocol and storage is the first point where mistakes are made. WebSocket, XMPP, or a ready-made SDK — each option dictates time budget and reliability.
-
Ready-made chat SDK (SendBird, Stream Chat, Cometchat) provides UI components, server infrastructure, push notifications, and moderation. Fast, reliable, but vendor lock-in and recurring costs. For MVP — optimal. One client cut time-to-market by 2 months using Stream Chat.
- Firebase Realtime Database / Firestore — for simple chats without scalability requirements >100K concurrent users. Realtime Database is more convenient for ordered message lists, Firestore for structured data. Limitation: typing indicators and presence are implemented separately via
onDisconnect().
- Custom backend with WebSocket — full control, maximum customization. Stack: Node.js +
socket.io or Phoenix Channels (Elixir), PostgreSQL + Redis for pub/sub. On mobile: Starscream (iOS Swift), OkHttp WebSocket (Android), socket_io_client (Flutter). Requires 2–3x development time but gives zero vendor risk. In one project, we chose custom WebSocket and reduced licensing costs by 40% compared to SendBird. Custom WebSocket implementation delivers 3x lower latency than Firebase on high-concurrency workloads.
Why is it important to plan offline mode in advance?
Offline mode is the most labor-intensive part of any chat. Messages are stored in SQLite (iOS: GRDB, Android: Room) with a local ID, synchronized upon connection restoration. Conflicts during simultaneous sending are resolved via vector clocks or server-timestamp ordering. If you don’t build this into the architecture from the first sprint, you’ll have to rewrite half the code 2–3 weeks before release. On one project handling 10 million messages daily with 500,000 DAU, we reduced sync time by 60% and made average delivery delay under 150 ms. Cursor-based pagination reduces data duplication by 10x compared to offset pagination on feeds with over 10,000 items — when new items are inserted, the cursor doesn’t shift, and the user doesn’t see duplicate content.
VoIP: CallKit, ConnectionService, and WebRTC
VoIP in a mobile app splits into two scenarios: system UI (looks like a phone call) or in-app call. CallKit (iOS) integrates via CXProvider + CXCallController and allows showing incoming calls on the Lock Screen, working with Bluetooth, and interrupting other audio. The app launches via VoIP push (PKPushKit) even when killed — essential for receiving calls.
On Android, the analog is ConnectionService API. Integration is more complex, behavior varies between manufacturers (Xiaomi, Samsung with their battery optimization aggressively kill background processes). WebRTC — transport protocol for P2P media. Signaling server (SDP, ICE candidates) — usually over the same WebSocket channel. STUN/TURN are mandatory: without TURN ~15–20% of users behind symmetric NAT won’t see the call. coturn — open source solution, Twilio NTS and Metered TURN — managed.
| Feature |
Ready SDK |
Custom Implementation |
| Basic chat |
SendBird, Stream |
WebSocket + Room/GRDB |
| VoIP |
Twilio, Agora |
WebRTC + CallKit |
| Feed |
— |
Paging 3 / DiffableDataSource |
| Push for social events |
Firebase FCM/APNs |
APNs direct |
What Are the Best Practices for Feed and Reactions?
Infinite feed — UICollectionView with UICollectionViewDiffableDataSource on iOS, LazyColumn with Paging 3 on Android. Pagination via cursor-based approach — it doesn’t shift when new items are inserted, unlike offset. Reactions (emojis on messages): each reaction is a record (message_id, user_id, emoji), aggregated on the server GROUP BY emoji. WebSocket event reaction_added updates the counter in real-time. Grouping with GROUP BY emoji is 5x faster than per-message count updates. Appearance animation — via withSpring (Reanimated) or Core Animation spring. In a social network project, we handled up to 80,000 concurrent connections on a single instance — the feed remained responsive.
Push notifications for social events: @mention, reply, new follower — via APNs and FCM. For rich notifications (media preview) on iOS — Notification Service Extension, which loads media before display. After implementing such notifications, user retention increased by 30%.
What deliverables do you receive?
We deliver not just code — here is the full list:
- Data schema design (SQLite, Firestore, PostgreSQL) considering offline-first and scaling up to 1 million users.
- Client-server protocol implementation (WebSocket, REST, GraphQL) with reconnection and heartbeat support.
- Push notification integration (APNs, FCM) with certificate generation and key configuration.
- TURN server setup or managed provider selection (e.g., Twilio NTS) for VoIP.
- API documentation and migration schema (including rollback plan).
- Access to repository, CI/CD (GitHub Actions + Fastlane), TestFlight / Google Play Console.
- Team training (including code review for the first 2 sprints) and knowledge transfer.
- On-call support for 2 weeks after release.
How to avoid typical mistakes in chat development?
- Lack of reconnection strategy. Client simply disconnects without a queue of unsent messages. Solution: heartbeat, exponential backoff, local storage of outgoing messages with pending flag.
- Using offset pagination in feed. When new posts are inserted, the user sees duplicates — scrolling breaks. Solution: cursor-based pagination.
- Ignoring battery optimization on Android. ConnectionService doesn’t survive until incoming call. Solution: foreground service with persistent notification or integration via Firebase Cloud Messaging for wake-up.
- Error in choosing chat protocol. Bare WebSocket without a protocol on top — reinventing the wheel. Platform-agnostic JSON or MessagePack with type flag.
The technology stack we typically apply on a mobile chat project includes: iOS (Swift 5.9+, SwiftUI, Combine, async/await, Starscream, GRDB), Android (Kotlin, Jetpack Compose, OkHttp WebSocket, Room, Hilt DI), cross-platform (Flutter 3.x/React Native), backend (Node.js + socket.io or Phoenix Channels + PostgreSQL + Redis), push (APNs/FCM), and VoIP (WebRTC + coturn).
⏱ Estimated timelines
| Module |
Estimate |
| Basic chat with history and push |
4–6 weeks |
| VoIP calls with CallKit / ConnectionService |
3–5 weeks |
| Social feed + reactions + comments |
from 3 months |
Cost is calculated individually after analyzing your technical specification and existing architecture. Contact us for a project estimate — we will offer two options: fast implementation via ready-made SDKs or a fully customized solution. Get a consultation and accurate estimate within 2 business days. Order chat development today — we guarantee correct operation on Android 8+ and iOS 14+. Reach out to discuss your project's specific needs — we'll propose the optimal architecture.
