D4 group

Boutique Design Agency and Mobile Development


Have experience developing complex mobile apps from scratch. Pro with Swift and Objective-C. Have implemented a wide variety of 3rd party APIs like Stripe, Firebase, Google maps, Twillio, etc. Work with Postman and many backend and database types. Skills: - Swift / Kotlin / React Native / Flutter - Native app development (iOS / Android) - Cross platform mobile development (iOS / Android) - Custom app development (iOS / Android) - App UX/UI design (iOS / Android) - App porting (iOS / Android) - App testing (iOS / Android) - Apps upgrade and maintenance (iOS / Android) Experience in apps development: - Startups Apps - Messaging Apps - Social Apps - Healthcare Apps - Delivery Apps - Booking Apps - E-Book Apps - Logistic Apps - Fin-Tech Apps iOS Tech-Stack: Xcode iOS stack Swift / Objective-C MVC / MVP / MVVM iOS SDK Twilio / Agora / Element Complex animations & responsive UI Cocoa Framework CocoaPods CocaTouch AVFoundation AVCaptureSession AVAudioSession Audio Unit AutoLayout Core Animations Core Audio Core Bluetooth Core Data Core Location Postgresql, MSsql Firebird / Interbase Firebase In-App Purchase Localization Storyboard JSON, REST API Push notifications Git (Github / Gitlab / Bitbucket) iBeacons / Bluetooth / IoT Mobile Apps Geolocation & Maps Android Tech-Stack: Android studio Java / Kotlin MVP / MVVM / Clean Android SDK Complex animations & responsive UI Coroutines 3rd party frameworks Twilio / Agora / Element Google Play Services Android Support Library Bluetooth Core Dagger 2 Kodein Glide Picasso Room JSON, REST API Push notifications Git (Github / Gitlab / Bitbucket) Firebase iBeacons / Bluetooth / IoT Mobile Apps Geolocation & Maps

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Web & Mobile Design

- User Experience Design (UX); - User Interface Design (UI); - User Flows & Prototypes; - SaaS Product Design; - Web & Mobile Design.


User Experience
Web Design
User Interface Design
Mobile App Design
UI Graphics
Mobile App Development
User Experience Design
UI/UX Prototyping
Mobile App
Mobile App Redesign
User Flow
Responsive Design
Design Writing
Website Redesign
100% Job Success
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Member since

Feb 8, 2017

Company information

Agency size

11-50 workers

Year founded


Client focus

Large business

Medium business

Very small business

Small business


English: Native or Bilingual
Ukrainian: Native or Bilingual