Apps by HanzCodes

You can open the apps on this page straight from your phone's browser, with no need to download them from the Play Store. Five of them are free.

Ready to use: Open to the public and ready to use now.
Prototype: A sample app for demonstration, not an official service.
On request: Installed on the client's own server, meaning the computer that stores the office's apps and data.

BukuGembok

Ready to useFor neighbourhood associations (RT), rotating savings groups (arisan), and farmer groups

A shared cash book that no one can change in secret. Each entry is marked by the phone that created it. If someone changes a figure on their own, the change is rejected when the members' phones bring their records into line. The app also works without internet.

Technical details

Progressive web app (PWA) under 300 KB. Each transaction is cryptographically signed on the device. Phones sync with each other by QR code or over the local network, with no central server, no account, and no email.

Open the app BukuGembok (external site)

More about BukuGembok

QRIS-EDC

Ready to useFor traders and small businesses

Your phone becomes a QRIS payment terminal (QRIS is Indonesia's standard for QR code payments). Type in the amount, and the customer scans a QRIS code that already shows that amount.

Technical details

Offline-first PWA. Dynamic QRIS codes are generated on the device, with no cashier hardware. The app was first developed for the PIDI Digdaya X Hackathon 2026 (Bank Indonesia and LPPI, the Indonesian Banking Development Institute).

Open the app QRIS-EDC (external site)

More about QRIS-EDC

NotaKita

Ready to useFor residents, neighbourhood associations (RT), and cooperatives

Records of informal loans (kasbon, money owed and lent) between neighbours. Once both sides agree a record, one side alone cannot change it. The app keeps working without internet.

Technical details

Local-first PWA with no server. Records are signed on the device (secp256k1) and exchanged by QR code or over the local network (WebRTC). Data is stored with CRDTs (Yjs) in IndexedDB, so records made at the same time do not overwrite each other.

Open the app NotaKita (external site)

More about NotaKita

SAVIS

Ready to useFor soybean farmers

Take a photo of a soybean leaf, and the app estimates whether the plant is short of nutrients. The app runs on the phone without internet, and the photo is not sent anywhere.

The AI model, which is the part that recognises the condition of the leaf, was developed by Hasby Asshiddiqi from his research. HanzCodes built the app.

Technical details

The classification model runs on the device, inside an offline-first PWA. Using it takes three steps.

Open the app SAVIS (external site)

More about SAVIS

LMS Adaptif

Ready to useFor schools. Current material: grade XI senior high school (SMA) biology

An online learning app for students. It suggests material based on the results of a pre-test, helps students search for material using ordinary sentences, and marks short essay answers automatically.

Technical details

Developed from the founder's undergraduate thesis. The BGE-M3 embedding model is used for semantic search and material recommendations. Essays are marked using cosine similarity against the answer key.

Open the app LMS Adaptif (external site)

More about LMS Adaptif

JombangSatu

PrototypeFor demonstrations to local governments

A sample one-stop public service portal (website). It includes residents' complaints, a queue for licensing counters, a digital guest book, and a leadership dashboard, meaning a screen that summarises data for senior officials.

JombangSatu is a prototype made by PT Hanz Kode Terpadu for demonstration. This portal is not an official service of the Jombang Regency Government. Please do not send real complaints through it.

Open the prototype JombangSatu (external site)

Digital signatures

On requestFor government agencies and companies

Electronic signatures for PDF documents. The app is installed on your office's own server, so documents do not leave the office.

Signatures from this app are uncertified electronic signatures. For documents that must carry a certified electronic signature, agencies still need an Electronic Certification Provider (Penyelenggara Sertifikasi Elektronik), such as BSrE, the government's electronic certification body. The difference between certified and uncertified electronic signatures.

Technical details

Based on DocuSeal, open-source software under the AGPL licence. We install it on a Linux server, set up the reverse proxy and HTTPS, and then maintain it.

Custom versions and support

Government agencies or companies that want to use a custom version of these apps on their own server can contact us.

We develop and fund these free apps ourselves. If they help you, you can support them.

Support the apps