Apps
Emberlo
Money for two, without the argument. A home-money app for Vietnamese couples.
Live · iOS · Android
How it is built
What it is
A home-money app for couples in Vietnam: a shared jar, private pockets, quick expense entry, a household money agreement, a Tết plan, a wedding and funeral gift book, and receipt warranties.
Who it is for
Couples in Vietnam. Vietnamese first, with English.
Stack
React Native for iOS and Android, on a shared Rust core with SQLite.
Architecture
Money is stored as whole numbers in VND, never as floating point. Shared data is end-to-end encrypted and synced through a relay that only holds sealed packages, which expire after 14 days. A private pocket never syncs to the other person’s phone. Photos are not synced or backed up.
Features
- A clear shared jar. Private pockets stay private
- Log an expense in a few taps
- Household money agreement and Tết plan (lunar calendar 2024–2045)
- Gift book and receipt warranties
Quality
40 test files across Jest, Rust and cross-layer tests.
Status
Live on iOS and Android.
What we learned
For money between two people, privacy is a feature: what stays on one phone matters as much as what syncs. Getting the currency model right on day one avoids rounding errors later.
Teardown: decisions and trade-offs
| Decision | Why | Trade-off |
|---|---|---|
| React Native app on a shared Rust core | Money logic, SQLite storage and encryption written once for iOS and Android. | A bridge layer between JavaScript and Rust to maintain. |
| VND stored as integers | No rounding drift on money. | Formatting is handled at display time. |
| Private pockets never sync | What is private stays on your phone, by design. | A private pocket is not on your partner’s phone or in a backup. |
| End-to-end encrypted sync through a relay. Sealed packets expire after 14 days | The relay cannot read household data. | A phone offline for longer has to resync. |
Questions
What is Emberlo?
A home-money app for couples in Vietnam. It has a shared jar, private pockets, quick expense entry, a household money agreement, a Tết plan, a wedding and funeral gift book and receipt warranties.
Who is it for?
It is for couples in Vietnam. The app is Vietnamese first, with English.
Do private pockets sync?
No. A private pocket never syncs to your partner’s phone or to a backup. What is private stays on your phone, by design.
How is shared data protected?
Shared data is end-to-end encrypted. It syncs through a relay that only holds sealed packages, and they expire after 14 days. The relay cannot read household data.
Which devices does it run on?
It is live on iOS and Android.
How does it store money?
It stores amounts as whole numbers in VND, never as floating point. That avoids rounding drift.