We build digital products that actually get used — not just shipped.
Jostar grew from hundreds of freelance projects into a studio building mobile apps, web apps, and an ecosystem of tools for Indonesian professionals and small businesses.
A new brand, led by a developer with a track record since 2020
Jostar launched in June 2026 as a software house led by Yosua Tarigan. Before that, Yosua worked as an independent app developer since December 2020, completing 263 orders for 181 clients on Fastwork.
Jostar is not yet a registered legal entity and is currently run directly by its founder.
Quick facts
- Name
- Jostar
- Launched
- June 2026
- Founder
- Yosua Tarigan
- Location
- Medan, Indonesia
- halo@jostar.id
- Status
- Not yet a registered legal entity
Numbers you can verify yourself
The founder's track record on Fastwork since December 2020 — public numbers, not internal claims.
From a single freelance order to a studio
No big leap — just projects finished one by one, and clients who came back.
- 01December 2020
It started on Fastwork
It all began with freelance projects on Fastwork. Step by step we became a top freelancer for mobile app development, with a 100% completion rate and clients who kept coming back.
- 02Specialisation
Going all in on mobile
Flutter became our default: one codebase for Android & iOS with native-quality results. It produced apps for event operations, mosques, AC service businesses, healthcare, local ride-hailing, and educational games.
- 03June 2026
Jostar launches
Two missions we hold to: helping clients build custom products, and providing an ecosystem of SaaS tools that serve professionals and small businesses in Indonesia.
- 04Today
The Jostar tool ecosystem
Invoices, CVs, certificates, formal letters, and a freelancer CRM — our own products, free for anyone to try, and living proof of the quality we build.
Four things we never compromise on
Handing a project to a developer is a big decision. So we carry the risk with you, instead of leaving it all on you.
Used, not just shipped
Features are judged by whether people actually use them. If one adds no value, we suggest cutting it — not billing for it.
Progress you can see
Regular WhatsApp updates with previews, and milestone-based payments — never everything up front.
Code & access are 100% yours
Repository, hosting, and database are handed over in your name. No lock-in to us.
Fast replies
Usually answered within minutes during working hours, plus a 30-day bugfix warranty after handover.
One partner, from idea to production
Operations systems, customer apps, and AI all happen in one place — no finger-pointing between vendors.
Business Operations Systems
Orders, schedules, inventory, field teams, and financial reports in one system — no more manual recaps or data scattered across chats.
Customer-Facing Apps
Android, iOS, and web apps where customers book, shop, and pay — wired straight into the system behind them.
AI That Does the Work
AI connected to your business data — answering customer questions, reading photos and documents, writing content. Not a bolted-on chatbot.
Startup MVPs & Products
From idea to a product ready for market testing, on a foundation that can grow into a SaaS — and the source code is entirely yours.
Apps already running in their users' hands
A few screens from projects we have shipped — from field operations to consumer-facing services.
Got an idea you want built?
Tell us what you need — we will help map out the features, the estimate, and the most sensible way to start.