Formulus
Offline-first bespoke data collection apps from Open Data Ensemble
- Developer
- Open Data Ensemble
- License
- MIT
- Package
org.opendataensemble.formulus- Category
- Internet
- Latest version
- 1.4.0 · Oct 18, 2026
- Minimum Android
- Android 7.0
Screenshots
Description
Formulus is the mobile data collection client of the Open Data Ensemble (ODE) platform.
It allows organizations, research teams, and public sector institutions to build their own bespoke data collection applications based on structured forms defined using the JSONForms specification.
Forms and application logic are defined externally, meaning the same Formulus app can host many different data collection projects without requiring app updates.
Key features include:
• Flexible form-based data collection using JSONForms
• Offline-first operation for use in the field
• Secure bi-directional synchronization with an ODE Synkronus server
• Support for complex data structures and validation
• Designed for long-term maintainability and open standards
Formulus is particularly suited for environments where reliable data collection is needed under challenging conditions, such as:
• field research
• public health surveillance
• environmental monitoring
• humanitarian and development projects
• decentralized data collection initiatives
The app requires access to an ODE Synkronus server for synchronization and project management. Organizations typically run their own Synkronus server to host forms, manage users, and collect submitted data.
If you do not yet have access to a Synkronus server but would like to explore the application, a public demonstration environment may be available. See the project website for details.
Formulus is part of the Open Data Ensemble ecosystem, an open-source initiative focused on building interoperable tools for decentralized, standards-based data collection.
Source code and documentation:
https://opendataensemble.org
It allows organizations, research teams, and public sector institutions to build their own bespoke data collection applications based on structured forms defined using the JSONForms specification.
Forms and application logic are defined externally, meaning the same Formulus app can host many different data collection projects without requiring app updates.
Key features include:
• Flexible form-based data collection using JSONForms
• Offline-first operation for use in the field
• Secure bi-directional synchronization with an ODE Synkronus server
• Support for complex data structures and validation
• Designed for long-term maintainability and open standards
Formulus is particularly suited for environments where reliable data collection is needed under challenging conditions, such as:
• field research
• public health surveillance
• environmental monitoring
• humanitarian and development projects
• decentralized data collection initiatives
The app requires access to an ODE Synkronus server for synchronization and project management. Organizations typically run their own Synkronus server to host forms, manage users, and collect submitted data.
If you do not yet have access to a Synkronus server but would like to explore the application, a public demonstration environment may be available. See the project website for details.
Formulus is part of the Open Data Ensemble ecosystem, an open-source initiative focused on building interoperable tools for decentralized, standards-based data collection.
Source code and documentation:
https://opendataensemble.org
All versions
| Version | Released | Minimum Android | Size |
|---|---|---|---|
| 1.4.0 (4 builds) | Oct 18, 2026 | Android 7.0 | 34.9 MB |
| 1.3.0 (4 builds) | Aug 26, 2026 | Android 7.0 | 34 MB |
| 1.2.0 (4 builds) | Jul 20, 2026 | Android 7.0 | 33.9 MB |
| 1.0.1 (4 builds) | Jun 22, 2026 | Android 7.0 | 33.7 MB |
How to install an older version of an Android app · How to install an APK file on Android
From the developer (GitHub)
APK files published by the developer on GitHub. They are signed by the developer and may not install over the other builds on this page (different signature). Links open github.com.
v1.3.1
· Aug 26, 2026
formulus-v1.3.1-36-armeabi-v7a-release-20260826.apk
30.4 MB formulus-v1.3.1-37-arm64-v8a-release-20260826.apk
35.8 MB formulus-v1.3.1-38-x86-release-20260826.apk
36.9 MB formulus-v1.3.1-39-x86_64-release-20260826.apk
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