05.09.2026 aktualisiert
Premiumkunde
100 % verfügbarMobile App Agentur | Kotlin Multiplatform | iOS & Android | Entwickler-Vermittlung
Rodgau, Deutschland
Weltweit
Abitur | Mathematikstudium (berufsbegleitend, laufend)Über mich
Zeise Digital ist eine Mobile-App-Agentur aus dem Rhein-Main-Gebiet, spezialisiert auf Kotlin Multiplatform für iOS und Android. Wir entwickeln Projekte als Subunternehmer und vermitteln erfahrene Entwickler für Android, KMP, TypeScript und UI/UX.
Skills
SupabaseRamlUser Experience (UX)Agile MethodologieAndroidAndroid Application DevelopmentAndroid NDKAndroid StudioIpad AppApple IOSSoftwareanwendungenAppstoreMobile Application DevelopmentMobile Device ManagementGitHub
Zeise Digital — Mobile App Agency | Rodgau, Rhine-Main, Germany
Who We Are
We are a specialized mobile app agency based in the Rhine-Main region of Germany, focused on building high-quality mobile applications for iOS and Android. Our core technology is Kotlin Multiplatform (KMP), which allows us to build a single shared codebase that runs natively on both platforms. This gives our clients a significant economic advantage over traditional approaches where separate teams build and maintain two entirely different apps. With KMP, every feature ships to both platforms at once, bugs get fixed in one place, and long-term maintenance costs stay low.
Our in-house team covers the full project lifecycle: a senior UX/UI designer handles all product design, a backend developer builds scalable server-side infrastructure in Node.js and TypeScript, and our KMP engineers take care of all mobile development across iOS and Android. Jakob Zeise, founder and managing director, leads every client engagement personally from first contact through delivery and beyond.
What We Do
Full-Service App Development
We take projects from idea to App Store, covering every step:
- Requirements engineering and product definition
- UX/UI design in Figma
- Cross-platform development with Kotlin Multiplatform
- Backend development with Node.js and TypeScript
- REST API design and third-party integrations
- App Store submission and release management for iOS and Android
- Long-term maintenance and feature development via retainer
Developer Staffing and Subcontracting
We support IT consulting firms, staffing agencies and technology companies across the DACH region with experienced development talent. All profiles can be engaged either through Zeise Digital as a subcontractor or directly as freelancers, depending on your preferred setup.
Our available profiles:
- Senior Android / Kotlin / KMP Developer (international) — 60 €/h
- Mid-Level Android / Kotlin / KMP Developer (international) — 45 €/h
- Mid-Level Web & Backend Developer, TypeScript (international) — 40 €/h
- Senior UI/UX Designer (international) — 35 €/h
- Junior Developer, Python / TypeScript (German) — 40 €/h
Reference Projects
ManeMap - a comprehensive horse management app for tracking health data, appointments and documentation, currently live on the App Store. . TextMentor - an AI-powered German language learning app designed specifically for schools. UnitedCall - migration of an existing Cordova app to a fully native Kotlin Multiplatform app including complete UI redesign. Further projects in the gaming, service and education and gastronomy sectors are in active development.
Feel free to reach out for project inquiries, subcontracting arrangements, or to request detailed developer profiles and CVs.
Erfahrung
Berufserfahrung5 - 10 Jahre
Freelancer seit2020
Sprachen
DeutschMutterspracheEnglischMutterspracheSpanischverhandlungssicher
Projekthistorie
Project Overview Migration of a B2B telephony application from Cordova to Kotlin Multiplatform (KMP) for iOS and Android, including a complete UI redesign. The app enables business customers to centrally manage multiple phone numbers, track incoming calls, and identify callers and their reasons for contact.
Challenge The legacy Cordova app suffered from significant performance limitations, restricted access to native device APIs, and increasingly high maintenance overhead - making a full platform migration the only sustainable path forward.
Deliverables
- Full migration to Kotlin Multiplatform with a shared codebase for iOS and Android
- Complete UI redesign aligned with modern mobile design standards
- Native push notifications (Firebase for Android, Apple Push Notification Service for iOS)
- Badge notifications, admin panel and cross-status search functionality
- Faster release cycles and significantly reduced maintenance effort
Result Both apps launched successfully on the App Store and Google Play in October 2025. The client confirmed: "The app runs natively on iOS and Android, is significantly faster and provides an intuitive experience for managing calls, callback requests and contact reasons. Communication was fast, deadlines were met. Clear recommendation." Ongoing maintenance contract in place since 2026.
Project overview: Full-cycle development of an AI-powered German writing correction app for grades 5–11. Students submit texts via typing, voice recording or handwritten photo — the AI returns color-coded corrections with student-friendly didactic explanations and audio feedback.
Features delivered:
- Text input via manual typing, speech-to-text (OpenAI) and OCR/handwriting recognition (photo upload)
- AI correction engine: color-coded by category — spelling, grammar, punctuation — with per-error rule references
- Audio feedback via ElevenLabs TTS — corrections read aloud in natural German voice
- Dictation mode "Schreib was du hörst": 3 difficulty levels (40–150 words), AI-generated connected texts
- iPad-optimized UI, German & English localization, DSGVO-compliant EU architecture
- Coming Soon screens for teacher dashboard, class management and learning analytics
Additional scope: Pitch deck, investor & foundation funding pages and full landing page (textmentor.de) — created by Zeise Digital alongside the app to support school rollout and grant applications
Tech stack: Kotlin Multiplatform · OpenAI GPT-4o Mini · ElevenLabs TTS · Gemini OCR
Process:
- Requirements & UX analysis for school/EdTech context, Figma design
- KMP development: shared codebase for iOS and Android
- AI pipeline: OpenAI correction, ElevenLabs TTS, OCR integration
- App Store launch (iOS, January 2026) — 1,500+ institutional downloads
One app. Every classroom. AI feedback at scale.
ManeMap — Horse Management App iOS & Android · Kotlin Multiplatform · launched February 2026
Project overview: Full-cycle development of a premium horse management app for The Rohns UG. From initial requirements to App Store launch — one shared KMP codebase for iOS and Android, with iterative design and integrated AI.
Features delivered:
- Horse profiles with breed, gender, weight tracking, microchip ID and medical card (vaccinations, medications, allergies, specialist visits)
- Training module: session logging, activity heatmap, 10+ exercise categories, structured training programs with images and pro tips
- Finance module: expense tracking by category, annual budget, monthly and yearly charts
- AI assistant "Milo": Gemini 2.0 Flash via Supabase Edge Functions with pgvector RAG for veterinary knowledge base
- Calendar with 14 event types: vet, farrier, vaccination, deworming, training, competition and more
- Info Hub: 8 content categories, daily tips, 3-day weather forecast with riding conditions
- Onboarding, Google & Apple Sign-In, dark mode, DE/EN localization
Process:
- Requirements analysis, PRD and design review
- Iterative UX/UI design in Figma with multiple client feedback rounds
- KMP development: shared business logic, native UI layers per platform
- Supabase backend setup, Gemini AI integration, pgvector knowledge base
- App Store & Google Play launch, post-launch in-app subscriptions via RevenueCat
One codebase. Two platforms. Full lifecycle delivery.