iOS · ANDROID · FLUTTER · REACT NATIVE · SINCE 2010
Upkeep.pro, the service-booking marketplace we built for global beauty and home-service professionals, is currently doing 500,000+ appointments booked daily across 10,000+ professionals worldwide. Our in-development AI-powered Caregiver EVV app uses Flutter, biometric authentication, GPS verification, and face-detection anti-fraud — engineered to work inside client homes where cellular coverage is unreliable. Apps that survive year two of production, not just the App Store screenshots.
48-hour response · NDA on request · Your first call is with an engineer
THE PROBLEM
Agencies that win mobile pitches are usually the ones with the prettiest mockup deck. The apps that survive in production are usually built by a different kind of team. The difference shows up at battery — the app that polls the API every 5 seconds drains the user’s battery and gets uninstalled in week two. At signal — the app that assumes constant 4G fails the moment a caregiver enters a basement or a delivery driver crosses a rural patch. At App Store / Play Store policy — the privacy-policy-shaped hole that gets the app rejected after launch and pulled from the store for 3 weeks while the agency disappears.
And it shows up at day 400. The launched app needs OS updates (iOS 17 deprecates the location permission flow you used; Android 14 changes background-service rules), payment SDK migrations (Stripe v5 breaks the v3 integration), and accumulated edge cases (the one user in Brazil with a Samsung A03 whose camera permission silently fails). The agency that built it has long since moved on. The product owner is back on the market for a vendor who can take it over.
We’ve been shipping mobile apps since before the App Store had a search bar. Our most-trafficked deployment — Upkeep.pro — processes more than half a million bookings a day, and we’re still on it. We architect for year-three, not for the App Store screenshot.
OUR APPROACH
We don’t default to Flutter, React Native, or native. We pick per project, based on your actual constraints: hardware integrations (biometric, GPS precision, BLE, camera-heavy), update cadence, team skill, and 5-year maintenance cost. Deliverable: a written platform recommendation with reasoning, architecture sketch, and a fixed-price quote for the build phase.
Mobile architecture is offline-first or it’s broken. We design the local-cache layer, the sync strategy, the queue-and-retry logic, and the conflict-resolution rules before writing screens. Push notifications, deep linking, payment SDKs, biometric prompts, and OS permission flows mapped end-to-end — not bolted on in week 10.
Two-week sprints. End-of-sprint TestFlight + internal-track Play Store builds on real devices in real network conditions — not just the iOS simulator. We instrument crash reporting, analytics, and performance monitoring from sprint one so you have data the moment beta users touch the app. Dedicated Slack channel, weekly written status.
We handle the App Store + Play Store submissions, the privacy-policy and data-handling manifests, the response to first-round reviewer feedback, and the OS-version upgrade treadmill. Upkeep.pro and the Karixa Caregiver app are both on this model. Hours scale to your roadmap; we don’t disappear after launch.
CATEGORIES WE SHIP
The common thread: real users, real money, real edge cases. We’ve shipped each of these to production.
Pattern: Dual-sided marketplaces with provider + consumer apps, search/match, in-app booking, reviews, in-app payments, automated reminders.
Reference deployments: Upkeep.pro (500K+ daily appointments, 10K+ professionals worldwide), Local Service Booking (Uber-for-services pattern).
Pattern: Real-time dispatch, GPS routing, driver mobile + admin web, delivery state machines, proof-of-delivery capture, courier offline mode.
Reference deployments: RabbitDispatch (goods delivery logistics platform), driver/operator apps for marketplace deployments.
Pattern: Mobile apps for field workers in client/customer environments. Biometric login, GPS-verified clock-in/out, face-match anti-fraud, offline read-only mode, AI voice-to-text for field notes.
Reference deployment: AI-Powered Adult Home Care Caregiver App (Flutter, in production-ready development, HIPAA-aligned, EVV-compliant).
Pattern: WebSocket-based live bidding, push notifications for outbid alerts, secure in-app payments, anti-fraud safeguards, leaderboard caching.
Reference deployments: Chase Bid mobile (lowest unique bid), TiptopBids mobile, Rubids iOS/Android.
Pattern: Sensor data ingestion, time-series dashboards on mobile, threshold alerting, push notifications for anomalies, BLE device pairing.
Reference deployment: Energyly (energy consumption monitoring + analytics application with IoT integration).
Pattern: Reliable push delivery (APNs / FCM with retry), geofenced targeting, incident-reporting with media capture, audit-grade delivery confirmation, multi-channel fallback (SMS/email).
Reference deployments: Zippy Alert (incident reporting + mass notification), Alacer (disaster management).
CASE STUDY DEEP-DIVE
Upkeep.pro operates a dual-sided service-booking marketplace connecting consumers with local beauty and home-service professionals — barbers, hairstylists, nail technicians, makeup artists, house cleaners, landscapers. Their tagline says it plainly: “Made With You In Mind.” They needed iOS, Android, and web apps for both sides of the marketplace (consumer-facing and provider-facing), with quick search, instant booking, in-app payments, automated reminders, business analytics, and the operational machinery to handle a marketplace that would eventually scale into the hundreds of thousands of daily bookings.
Native iOS and Android applications for both the provider and consumer experiences, plus the supporting web platform. Quick professional search and 1-to-2-minute booking flow. Verified-client review system, business profiles, online appointment scheduling and management. Automated appointment reminders for both sides of the booking. Client list import functionality so providers could migrate from their previous tools. Business analytics dashboard and provider automation tools. 30-day free trial onboarding flow for new providers. Real-time booking state machine sturdy enough to survive marketplace-scale traffic.
The platform now serves 10,000+ professionals worldwide with 500,000+ appointments booked daily. Upkeep.pro publicly claims 37% proven income growth for the service providers using the platform. The marketplace is live across iOS, Android, and web globally — including everything from individual practitioners to multi-location service businesses. Every number on this page is verifiable from upkeep.pro directly.
Marketplace apps live or die on the friction of the booking flow. Upkeep’s scale wasn’t accidental — it was engineered. We over-invested in three things from day one: the speed of provider search (sub-second response perceived as “instant”), the reliability of push notifications for booking confirmations (no “did my appointment go through?” ambiguity), and the soft-launch UX for new providers (so they got to a successful first booking inside their free trial, not after it). Five years in, those decisions are still paying back in the booking-throughput numbers.
TECH STACK
HOW WE ENGAGE
2–3 weeks · fixed fee
Best when you have an app concept but no architecture. We map your platform decision (native vs Flutter vs React Native), integration surfaces, offline requirements, and target user load. Deliverable: technical spec, platform recommendation, and a fixed-price quote for the MVP build.
3–6 months · fixed price
Best when you have a spec and need a fixed budget. We deliver iOS + Android (+web if needed) with backend APIs, payment integration, push notifications, App Store + Play Store submission, and a 90-day production warranty. Two-week sprints, real-device TestFlight + internal-track Play Store builds each sprint.
Monthly · time-and-materials
Best post-launch — or when you’ve inherited an app from an agency that disappeared. We audit the codebase, write a remediation plan, and either keep it running or rebuild the problem pieces. Hours scale to your roadmap (OS upgrades, payment SDK migrations, App Store policy updates, feature work).
Standard contracts: MSA + SOW templates available on request before our first call. Mutual NDA on request. Apple Developer / Google Play developer accounts can be held by you (recommended) or by us during build (transferred on launch). App store + Play Store submissions handled end-to-end.
QUESTIONS
2–3 weeks discovery, then 3–6 months for the MVP build depending on complexity. Single-platform consumer apps with simple flows: closer to 3 months. Cross-platform marketplaces with payment integration, dual-sided onboarding, and admin web: closer to 6.
We pick per project. Native (Swift/Kotlin) for apps with deep platform integration, biometric flows, BLE, or AR. Flutter for single-codebase apps where UI is custom enough that native widgets aren’t needed (our in-development caregiver app uses Flutter for this reason). React Native for teams that already speak React and where the use case doesn’t fight the framework.
Pricing model: fixed-fee discovery sprint, fixed-price MVP build, time-and-materials retainer post-launch. We quote firm numbers after a 30-minute discovery call. Ballpark range during our first conversation; fixed quote after discovery.
That’s exactly what the retainer is for. iOS and Android each release a major version per year that deprecates APIs, changes permission flows, and adjusts background-service rules. Apps without a maintenance retainer die on the OS upgrade treadmill. Upkeep.pro and the Karixa Caregiver app are both on retainer for ongoing OS-version work.
Yes — it’s one of our most common engagements. We audit the codebase, write a remediation plan, and either keep it running or rebuild the problem pieces. We’ve taken over apps where the original team disappeared, where the App Store rejected an update, or where the app started crashing in the field after an OS upgrade.
Yes. We handle the initial submission, the privacy-policy and data-handling manifests (App Privacy questionnaire on iOS, Data Safety form on Play Store), reviewer feedback responses, and the resubmission cycle if needed. You hold the Apple Developer + Google Play accounts; we operate them on your behalf during the build.
Offline-first is the default for any field-operations or remote-area app. We design the local cache, sync strategy, queue-and-retry logic, and conflict-resolution rules before writing screens. The Caregiver EVV app is a good example — it has to work in client homes where cellular coverage is unreliable.
We’re listed on Capterra at 4.8★ across 25 verified client reviews with verified reviewers across real estate, automotive, sports, non-profit, marketing, and auction industries. Read the reviews on Capterra →
Same engineering team. Same architecture bar. Your app, with a foundation that already proved itself at marketplace scale — and survived three OS upgrade cycles in production.
App failing on the OS upgrade treadmill? +977 9851038796 — Roshan Subedi, Founder & MD · takeover audits reviewed directly