Mobile Application Service

Mobile App Development

We design, build and ship iOS and Android apps that people keep on their home screen — from the first wireframe to the store listing, the crash reports and the version after that. One team, one contract, one number to call.

iOS · Android · Cross-platform Prototype before code Code & store accounts stay yours
What we build

Mobile services, from prototype to store

Design, engineering, back end, launch and support come from one team — so nothing falls through the gap between a design agency, a developer and a hosting provider.

iOS App Development

Native iPhone and iPad apps written in Swift and SwiftUI, built to pass App Store review the first time, with TestFlight builds your team can install from day one.

Swift · SwiftUI · Xcode · TestFlight

Android App Development

Kotlin and Jetpack Compose apps tested across the screen sizes and OS versions your customers actually carry, not just the newest flagship.

Kotlin · Jetpack Compose · Play Console

Cross-Platform Apps

One Flutter or React Native codebase serving both stores. The right choice when the app is content and forms rather than heavy device work — it cuts build and maintenance cost close to half.

Flutter · React Native · Expo · Dart

Progressive Web Apps

Installable from a link, works offline, updates without a store review queue. The fastest route to a mobile product when store distribution is not the point.

PWA · Service workers · Offline cache

UI/UX Design & Prototyping

Wireframes, visual design and a clickable prototype you can hand to a real customer — approved and signed off before a single line of app code is written.

Figma · User flows · Clickable prototype

Back End, API & Cloud

The half of the app nobody sees: accounts and login, push notifications, payments, data sync, file storage and an admin panel your staff can operate without us.

Node.js · Laravel · Firebase · PostgreSQL

Store Launch & ASO

Developer accounts, listing copy, screenshots, privacy declarations, review responses and a staged rollout — so launch day is a scheduled event, not a gamble.

App Store · Google Play · ASO · Staged rollout

Maintenance & Support

iOS and Android ship breaking changes every year. We keep the app compatible, triage crashes, watch the analytics and turn what we learn into the next release.

Crashlytics · Sentry · Analytics · SLA
Why a mobile app

Why a business would put an app on its customers' phones

An app earns its place when you need people to come back — repeatedly, without paying for the click each time. That is a specific claim, and it is worth testing against your own numbers before you commit a budget.

  • A permanent place on the home screenA direct channel to your customer that no ad auction, algorithm change or search ranking can take away from you.
  • Notifications people actually readA push notification lands where email and SMS no longer do — as long as you earn the right to send it and keep it relevant.
  • Works where the signal does notData cached on the device keeps drivers, field staff and customers working through a dead zone, then syncs when the connection returns.
  • Access to what the phone can doCamera and barcode scanning, GPS, biometric login, NFC, Bluetooth — the features a browser tab simply cannot reach.
  • Repeat purchases with less frictionSaved details and one-tap checkout shorten the path from intent to order, which is where loyalty programmes finally start to pay.

And when it is the wrong tool

We will say so during discovery, before you spend the budget. An app is a poor fit when:

  • Customers buy from you once or twice a year — nobody installs an app for that.
  • The product is content that changes daily and needs no device features.
  • There is no budget for the year after launch; an app is a subscription, not a purchase.
  • You cannot yet answer, in one sentence, why someone would install it.

In those cases we build a responsive website or an installable PWA instead — a fraction of the cost, and it reaches every phone without a store.

Technology

The platforms and tools we work with

We pick native or cross-platform after we understand the app — device features, performance, budget and how long you intend to keep shipping updates.

iOS

SwiftSwiftUIUIKit XcodeTestFlightApp Store Connect

Android

KotlinJetpack ComposeAndroid Studio Material 3Play Console

Cross-platform & front end

FlutterReact NativeExpo DartTypeScriptPWA

Back end, cloud & quality

Node.jsLaravelFirebase SupabasePostgreSQLFigma FastlaneSentry
What we have built

Apps by industry

Six categories that cover most of what our clients ask for — and where the return on an app is easiest to measure.

Retail & e-commerce

Catalogue, cart and one-tap checkout with saved details, plus push campaigns that bring buyers back without paying for the click again.

→ one-tap reorder
→ loyalty and vouchers
→ abandoned-cart push

Booking & services

Appointments for clinics, salons, repair and rental businesses: live availability, reminders that cut no-shows, and deposits taken in the app.

→ live availability
→ reminder notifications
→ deposit payments

Logistics & field operations

Driver and technician apps that keep working offline: route lists, barcode scanning, photo proof of delivery and signatures that sync when signal returns.

→ offline job list
→ barcode scanning
→ proof of delivery

Healthcare & clinics

Patient booking, results and reminders with biometric login and a permission model built for sensitive records from the first design session.

→ biometric login
→ appointment reminders
→ secure records access

Education & training

Lessons that download for offline study, progress tracking, quizzes and certificates — designed for a phone on a commute, not a desktop.

→ offline lessons
→ progress tracking
→ quizzes and certificates

Internal enterprise tools

Approvals, inventory counts, inspections and reporting for your own staff — distributed privately, without a public store listing.

→ private distribution
→ inspection checklists
→ approvals on the move
How we deliver

Six stages, each with something you can hold

Every stage ends in a deliverable you can open, click or install. Nothing moves forward until you have signed off the one before it, and you can stop at any stage.

Stage 01

Discovery & scoping

Who the app is for, the one job it must do well, and what stays out of version one. You leave this stage with a written feature list and a fixed estimate.

1–2 weeks→ product brief
Stage 02

UX & UI design

User flows, wireframes, then the full visual design in your brand. Delivered as a clickable prototype you can put in front of a real customer before we build.

2–3 weeks→ clickable prototype
Stage 03

Architecture & setup

Native or cross-platform decision, data model, API contract, environments and store accounts created in your name — all agreed in writing.

1 week→ technical plan
Stage 04

Build sprints

Two-week sprints, each ending in a build you install on your own phone. You see the app growing instead of waiting months for a reveal.

6–12 weeks→ build every 2 weeks
Stage 05

QA & device testing

Real devices across screen sizes and OS versions, slow and offline networks, plus a closed beta on TestFlight and Play so your team finds what we cannot.

2 weeks→ test report + beta
Stage 06

Launch & support

Store submission and review handling, staged rollout, crash and performance monitoring, then a maintenance plan and a documented handover to your team.

ongoing→ live in both stores
15+Years of experience
1,000+Projects delivered
30+Passionate team members
Engagement models

Three ways to start with us

Test the idea cheaply, build the whole product, or keep a team shipping releases every month. Pricing is quoted after discovery, so you never pay for scope we have not yet understood.

MVP Sprint

8 weeks · fixed fee

For teams who need a real app in real hands before committing to the full build.

  • Discovery and feature prioritisation
  • UX and UI design for the core flow
  • Working app on one platform
  • Beta distribution to your testers
  • Findings and a recommendation in writing
Scope an MVP

End-to-End App Build

3–6 months · milestone-based

The complete product: design, both platforms, back end, launch and handover.

  • Everything in the MVP Sprint
  • iOS and Android release builds
  • Back end, API and admin panel
  • Payments, push and analytics
  • Store submission and ASO
  • Monitoring, documentation and handover
Request a proposal

Dedicated App Team

Monthly · 2–6 engineers

For products with a roadmap, where release one is the beginning rather than the end.

  • Named engineers and a designer
  • iOS, Android and back-end coverage
  • Release train on your schedule
  • OS upgrades and crash response
  • Scale the team up or down each month
Discuss a team
Why CTG

The team that builds the app also runs everything around it

CTG has been delivering mobile apps, websites, hosting and management software for years. When the app, the API and the server come from one place, launch week stops being a negotiation between vendors.

01

One partner for the whole product

App, back end, admin panel, website and hosting from the same team. Nobody gets to say the problem belongs to someone else.

02

Design approved before code

You sign off a clickable prototype first. Changing a screen in Figma costs an afternoon; changing it after it is built costs a sprint.

03

You own the code and the accounts

Repositories, signing certificates, App Store and Play accounts are created in your company's name and stay there. No hostage situation at renewal time.

04

We stay after launch

Apps break when iOS and Android update, not when you change them. We plan for that year from the first estimate instead of surprising you with it.

Questions

What clients ask us first

Native or cross-platform — which should we choose?

Choose native when the app leans hard on the device: heavy camera work, Bluetooth, background location, complex animation, or a long roadmap where every millisecond matters. Choose cross-platform when the app is mostly screens, forms, lists and payments — Flutter or React Native then covers both stores from one codebase and cuts build and maintenance cost close to half. We make the recommendation during discovery and explain the trade-off in plain terms rather than defending a house preference.

How long does an app take, and what does it cost?

An MVP on one platform runs about eight weeks at a fixed fee. A full product on both platforms with a back end typically takes three to six months. We quote after discovery, because a number given before we understand your data, your integrations and your review requirements is a guess — and guesses get corrected later at your expense.

Do we need both iOS and Android at launch?

Often not. If you are testing an idea, launching on one platform first halves the cost and gets you real feedback sooner — pick the one your customers actually carry, which we check rather than assume. If the app is for the general public in Vietnam, Android usually reaches more people; for a premium or B2B audience, iOS often converts better. A cross-platform build makes the second store a small extra step later.

Who owns the App Store and Google Play accounts?

You do. We create the developer accounts in your company's name and add ourselves as members, never the other way round. The same applies to the repository, the signing certificates and the cloud project. If you ever change agency, you take everything with you and nothing stops working.

What happens after launch when iOS or Android updates?

Both platforms ship a major release every year, and each one deprecates something. Under a maintenance plan we test against the beta before it reaches your customers, update the build, and keep the store listings compliant with new privacy and permission rules. Without a plan, an untouched app usually starts breaking within twelve to eighteen months.

We are not sure we need an app at all. Can you tell us?

Yes, and we would rather do that than sell you one you do not need. The question we ask is how often a customer has a reason to come back. Weekly or more, an app pays for itself; once or twice a year, a responsive website or an installable PWA does the same job for a fraction of the cost. We say which one we think you need during discovery, and we have talked clients out of apps before.

Get started

Tell us about the app you have in mind

Describe who it is for and the one thing it has to do well. Within two working days you will get a written first opinion — native or cross-platform, a realistic timeline, and whether you need an app at all. No obligation, no sales call required.

We use your details only to answer this enquiry. Prefer email? Write to [email protected] or call 0912.80.50.86.