// Services by Martin Nzau (aka Monsiu)

Web & Mobile Development

Need a website, web app, or mobile app built? I design, build, and ship clean, fast software for individuals, startups, and businesses. Tell me what you have in mind below and I will get back to you with a plan, a timeline, and a quote.

Verified on Upwork: 100% Job Success, 5.0/5 rating - check my client reviews ↗

Start your project ↓ Proof first? See what I ship

Proof, Not Promises

ClauseShift: AI contract review

SaaS · AI Contract Review

ClauseShift

Reviews contracts clause by clause with citations, live on the web and in five app stores. Payments, auth, AI pipeline, monitoring: the whole stack.

WebGoogle PlayAmazonMicrosoftHuaweiZapstore
PesaShift: see every shilling M-PESA takes

Android · Fintech Analyser

PesaShift

Parses M-PESA PDF statements fully on-device and shows every fee and Fuliza charge. Launched August 2026; nothing ever leaves the phone.

AmazonHuaweiZapstoreDirect APKPlay · in review
Custom RR: a hub for custom ROMs and recoveries

Open Source · 4 Platforms

Custom RR

Custom ROM and recovery hub for Android, Linux, Windows, and macOS from one Flutter codebase, with a nightly data pipeline and localized store listings.

Google PlayAmazonF-DroidZapstoreMicrosoft
3products live
6app stores
4platforms
1developer, end to end

Every service on this page is something I have already shipped for myself: store review, CI pipeline, and all. Your project gets the same treatment.

Independently verified on Upwork - these numbers and reviews are public on my profile. Check them before you spend a dollar. ↗
100% Job Success 5.0 / 5 rating Rising Talent Identity verified
“Great to work with, 100% recommend.”Upwork client - April 2024
“Very patient et always trying to get things done. I recommend”Upwork client - January 2025

What I Offer

01 - Web

Web Services

From simple landing pages to full-stack web applications. I focus on performance, accessibility, and clean UX so your users actually enjoy using it.

  • Marketing & portfolio websites
  • Business dashboards & admin panels
  • E-commerce stores
  • Custom web apps (React, Next.js, Node.js)
  • APIs, auth, payments, integrations
  • Hosting, deployment & maintenance
02 - Mobile

Mobile App Development

Cross-platform mobile apps for Android and iOS, built with Flutter so you ship faster without sacrificing native feel.

  • Android & iOS apps (Flutter)
  • Firebase backend & authentication
  • Push notifications & offline support
  • Payment & API integrations
  • App store publishing
  • Ongoing updates & support

How It Works

01

Tell me your idea

The form below takes two minutes. Rough ideas are fine; part of my job is turning them into a concrete scope.

02

Plan & quote within 48 hours

You get scope, milestones, a timeline, and a fixed price. No obligation, no pressure to proceed.

03

Build with weekly demos

You see running software every week, not status reports. Feedback goes straight into the next iteration.

04

Ship it properly

Deployment, app store submission, and handover included. You own the code and the accounts, full stop.

What Things Cost

Landing / marketing site

from$500

Design, build, and deploy. Mobile-first, fast, SEO basics done right.

Web app / dashboard

from$1,500

Auth, database, payments, admin. React or Next.js with a proper backend.

Mobile app (Android + iOS)

from$3,000

One Flutter codebase, both platforms, store submission included.

App store submission (existing app)

from $150 / store

Code review & optimization

from $400

API / backend build

from $800

Maintenance & support

from $100 / mo

Anchors, not menus: every project is quoted individually, and the quote is fixed for the agreed scope before work starts. Compare freely - typical US agency rates run 5-10x these numbers for the same stack. Crypto payments welcome.

Request a Service

Back to Home

I reply within 24-48 hours with a real plan and a fixed quote, not a canned reply. Your request goes straight to my inbox; no account needed.

Prefer direct contact? contactmonsiu@gmail.com github.com/monsiu linkedin.com/in/martinnzau x.com/MonsiuTech Upwork (reviews)

Common Questions

Do you work with clients outside Kenya?

Yes. Most of my work is remote for clients abroad. I work async-friendly with clear written updates, and payment is flexible: crypto is welcome too.

Fixed price or hourly?

Fixed price for anything with a defined scope: you approve the quote before work starts and it does not creep. Hourly only makes sense for open-ended maintenance and support.

Who owns the code?

You do. Full source code and repository handover on final payment. No lock-in and no hosting hostage games.

How fast will I hear back?

Within 24 to 48 hours, with a real plan: scope, milestones, timeline, and a fixed quote. Not a canned reply.