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RYMTHOS®DEV
Independent design & engineering
Independent studio · est. 2024

Not just built.Built to work.

Custom websites, mobile apps, and the systems behind them. One engineering partner. From the first idea to a product you own.

01 / Web
100

100ToolCrate

100toolcrate.com

100+

Tools

0

Signups

1

Platform

Less searching.
More doing.

Live product ↗
02 / Mobile

Salah Companion

Flutter · open source

Free

05:12

Fajr · today

B

Billal Hossain2h

Prayer times, Qibla, a Quran reader, and a dhikr counter — offline first.

Fajr05:12
Dhuhr12:04
Asr15:20
Public repoInspect ↗
03 / Systems

Under the hood

Built
01ApplicationReact
02API layerNode
03DataPostgres
04DeployCI/CD
Postgres · RLS99.9% up
USD
01 / Selected workReal products. Open to inspection.

Less promise.More proof.

Two products you can explore for yourself. Not a wall of logos. A look at how I think, design, and build.

Web applicationLive product
100toolcrate.com
100ToolCrateMade to be useful

The utility crate for
modern creators.

100+ tools. One place. Less friction.

Search for a tool…⌄
◇JSON FormatterOpen tool
◇Image ToolsOpen tool
◇CalculatorsOpen tool
◇QR ToolsOpen tool

Interface preview · explore the live site below

Project 01  /  2024

100ToolCrate

A useful tool should solve your problem. Not become another one.

100+ browser-based converters, generators, and calculators in one custom-built platform.

REACT / TYPESCRIPT / TAILWIND

Explore the live product
Read the project notes
Mobile applicationOpen source
Salah Companion: Prayer Times on Google Play, published by Rymthos

Public app · public source

Project 02  /  2024

Salah Companion

Everyday utility. Privacy by design.

Prayer times, Qibla, a Quran reader, and a dhikr counter in a Flutter application.

FLUTTER / OFFLINE-FIRST ARCHITECTURE

Inspect the source code
Read the project notes
02 / CapabilitiesOne partner. The whole product.

From interfaceto infrastructure.

Start with the problem. We'll choose the right tools. Custom design and engineering, with a clear scope and a fixed quote before the build.

A distinctive brand website, a practical business platform, or your next SaaS product.

What you get

Custom interface design, responsive development, core user flows, and launch handover.

Typical timeline

7–14 days

REACT / TYPESCRIPT / FULL-STACK DEVELOPMENT

Native performance on Android, or one Flutter codebase for both stores.

What you get

Material 3 interface, offline-first storage, push notifications, and store submission handled end to end.

Typical timeline

10–21 days

FLUTTER / KOTLIN / REACT NATIVE

The database, APIs and infrastructure your product runs on.

What you get

Schema design, row-level security, REST and GraphQL APIs, payment webhooks, and deployment pipelines.

Typical timeline

10–18 days

POSTGRESQL / NODE.JS / SUPABASE

Storefronts that take real money and dispatch real orders.

What you get

Checkout, inventory, courier integrations, discount engine, and an admin dashboard you actually enjoy using.

Typical timeline

10–14 days

STRIPE / BKASH / PATHAO API

Voice agents, private knowledge hubs, and document pipelines.

What you get

Retrieval pipelines grounded in your own data, telephony integration, and human-in-the-loop review.

Typical timeline

7–12 days

OPENAI / LANGCHAIN / VECTOR SEARCH

For the site or app that has stopped being an asset.

What you get

Audit, security hardening, dependency rescue, and a migration plan with zero downtime.

Typical timeline

4–10 days

AUDITS / MIGRATION / HARDENING

Starting prices in USD. Final price and timeline depend on your agreed scope. No checkout, no surprise commitment.

03 / The approachClarity is part of the deliverable.

No black box.No guesswork.

You shouldn't have to wonder what's happening to your project. Here's what working together actually looks like.

The partnership standard

Your
product.
Your
code.
Your
control.

Built from scratch for your requirements. Handed over without a lock-in.

  • Direct access to the person building it
  • Scope and quote agreed before code
  • Source code and repository ownership
  • 30 days of post-launch defect fixes
01

Understand before building.

We talk about your business, customers, and the problem worth solving.

A SHARED GOAL & AGREED SCOPE

02

Make the plan tangible.

Requirements, a fixed quote, and a custom design you can review before development.

REQUIREMENTS & DESIGN SIGN-OFF

03

Build. Show. Refine.

Follow progress through a live staging link. Review the real product, not just status reports.

WORKING SOFTWARE & MILESTONE REVIEWS

04

Launch with ownership.

Testing, deployment, repository transfer, and a walkthrough. Plus 30 days of defect fixes after launch.

SOURCE CODE, DOCUMENTATION & HANDOVER

Md. Billal Hossain, founder of Rymthos Dev

Md. Billal Hossain / Founder

04 / The person behind the product

A direct line.
Not a relay race.

Hi, I'm Billal. I design the experience, write the code, and see it through.

I started Rymthos Dev to build custom digital products for founders who want a thoughtful engineering partner—not another layer of middlemen.

Based in Bangladesh, working with clients worldwide. From brand websites to mobile apps and full-stack systems, you work directly with me from discovery to handover.

Explore my GitHubLet's meet
05 / Good questionsThe practical details, without the fine print.

Before
we begin.

The practical details, without the fine print.

Every project starts from a published floor: $179 for a brand website, $349 for a mobile app, $349 for AI systems, $449 for e-commerce. You get a fixed quote after we agree the scope — never an open-ended hourly bill.

Most websites ship in 7–14 days and mobile apps in 7–21 days. Complex systems run longer. The timeline is part of the quote, and you follow progress on a live staging link from week one.

Me — Billal. I design, build, and deploy your product. There is no account manager, no hand-off to a junior team, and no relay race between departments.

Yes. The repository is transferred to you at handover, along with documentation and a walkthrough. Nothing is locked to my hosting or my tooling.

You get 30 days of free defect fixes, then an optional care plan covering updates, security patches, and small changes. If it changes what the product is, it becomes on-demand work quoted before we start.

07 / PricingFlat fees. Zero hourly surprises.

Agency craft.
Startup price.

Built with modern, AI-accelerated engineering to ship in days what legacy agencies take months to deliver. Every number below is a published starting point.

Starter

$800+

Portfolio, landing page, or high-trust personal brand site.

$179one-time

7–10 days

  • Up to 5 custom pages
  • Mobile-first responsive design
  • Contact form + Google Map
  • On-page SEO structure
  • 2 revision rounds
  • Headless CMS
  • E-commerce checkout
Most popular

Business

$2,500+

Conversion-focused marketing hub for growing brands and companies.

$349one-time

10–14 days

  • Up to 15 pages
  • Headless CMS + blog
  • Lead capture & analytics
  • Sub-second speed optimization
  • Polished micro-animations
  • 5 revision rounds
  • E-commerce checkout

E-Commerce

$3,500+

A complete store processing real payments and dispatching orders from day one.

$499one-time

10–14 days

  • Unlimited products & inventory
  • Stripe, PayPal, Apple Pay, Google Pay & Cards
  • Automated shipping & courier dispatch flow
  • Admin sales dashboard
  • Discount & coupon engine
  • Unlimited revision rounds
Market comparison · average business software & website
Typical agency$3,000–$10,0002–4 months
Freelance marketplaces$500–$2,000Unpredictable
Template resellers$200–$600Generic output
Rymthos DevStarts with $1797–14 days

Want the full picture?

Mix plans, add-ons, care, and hosting in the interactive calculator and see your exact number before you ever talk to me.

06 / Your next chapter

Good idea.
Let's build it.

Tell me what you're thinking. We'll work out the right next step together.

Free 30-minute strategy conversation.

No deposit. No obligation.

Let's talk on WhatsApp
rymthos.dev@gmail.com

A rough idea, your goal, and a timeline are a great start.

01 / Contact

Let's talk.

Whether you have a fully scoped brief or just a rough idea, send the details below. I read every message myself and reply within one business day.

Direct

rymthos.dev@gmail.comWhatsApp

What happens next

Scope and a fixed quote within 48 hours. Currently booking the next sprint.

Or