Cloud Backup

📋 Overview

Expense Tracker: Koala ("Koala") provides a cloud backup feature that lets you securely back up your bill data to the cloud and sync it across multiple devices. This guide will help you understand how to use cloud backup.

☁️ What Is Cloud Backup?

Cloud backup uploads your bill data to a cloud server to achieve:

• Data safety: Prevent data loss from device loss or damage
• Multi-device sync: Sign in with the same account on different devices and data syncs automatically
• Data recovery: Restore data to a new device from the cloud at any time

💡 Tip:

• Cloud backup requires signing in to an account (currently supports Sign in with Apple)
• The cloud applies access control and data isolation — only signed-in users can access their own data
• In most cases, syncing happens automatically; you can also trigger it manually from the Settings page

🔐 Sign In

Sign in with Apple

1. Open Expense Tracker: Koala
2. Tap the "Settings" icon in the bottom navigation bar
3. At the top of the Settings page, tap the user info card (when not signed in, it shows “Sign in with Apple”)
4. Follow the prompts to complete the Apple sign-in flow

📝 Note:

• After signing in, your data will automatically start syncing to the cloud
• The initial sync on first sign-in may take some time
• Please ensure your network connection is stable

🔄 Cloud Sync Mechanism

Automatic Sync

The system automatically syncs data at the following times:

• App launch: Automatically syncs account and ledger data
• After data changes: Creating, editing, or deleting bills automatically marks them for sync
• When switching ledgers: Silently syncs the current ledger's data (bills, categories, tags, etc.)

💡 Tip:

• Automatic sync runs in the background and does not affect normal use
• If the network is unavailable, data is stored locally and synced automatically when the network is restored

Manual Sync

1. Open Expense Tracker: Koala
2. Tap the "Settings" icon in the bottom navigation bar
3. In the upper-right corner of the Settings page, tap once the cloud sync icon (cloud icon) to trigger a sync manually
4. While syncing, the icon shows a loading animation; when it finishes, it returns to the cloud icon

⚠️ Note:

• Manual sync requires being signed in
• If you are not signed in, you will be prompted to sign in before syncing
• Please keep the app in the foreground during the sync process

View Sync Status (Sync Dashboard)

In the upper-right corner of the Settings page, double-tap the cloud sync icon (cloud icon) to open the “Cloud Sync Status” overlay, which shows the current sync state at a glance:

• Grouped by category: bills, accounts, ledgers, categories, tags, tag groups, transfers, mood records
• Each category shows the “synced count” and “pending count”, with an icon indicating whether the category is fully synced
• Tap outside the overlay to close it

💡 Tip:

• Tap once the cloud icon = manual sync; double-tap the cloud icon = view sync status
• A “pending” count of 0 for a category (green check) means that category is fully synced

Unsynced Indicator (Red Dot)

A red dot appears on the cloud icon in the upper-right corner of the Settings page to remind you that some data has not finished syncing:

• No red dot: all categories are fully synced
• Red dot shown: any category still has a “pending count”

💡 Notes:

• The red dot uses exactly the same logic as the double-tap overlay: if any row in the overlay has a non-zero “pending” count, the icon shows the red dot; when every row is 0, the red dot disappears
• Counts are scoped to the current ledger (bills, categories, tags, and tag groups are counted for the current ledger)
• The red dot refreshes automatically when you enter the Settings page, switch back to it, finish a manual sync, switch ledgers, sign in or out, and when a background sync completes; while you stay on the Settings page, it also updates automatically after a local change triggers an automatic sync
• While a sync is in progress the icon shows a loading animation, and no red dot is shown
• To see which data is not yet synced, double-tap the cloud icon to open the “Cloud Sync Status” overlay
• When you are not signed in (guest), any local data counts as unsynced and the red dot is shown; it disappears after you sign in and the sync completes

📊 Synced Content

Data Types That Are Synced

Cloud backup syncs the following data:

• Ledger data: Ledger names, descriptions, currencies, icons, etc.
• Bill data: All bill records (including amounts, categories, tags, notes, etc.)
• Account data: Account names, types, etc. (account balance is local data, is not uploaded, and is restored locally from bills)
• Category data: Expense and income categories (including parent/child categories)
• Tag data: Tag groups and tags
• Transfer data: Transfer records between accounts
• Mood data: Mood check-in records on the Overview page

Data That Is Not Synced

The following data is not synced to the cloud:

• App settings: Theme, language, and other local settings
• Cache data: Temporary cache data
• User preferences: Personal preference settings
• Exchange rate data: Fetched from the server on demand on this device
• Account balance: Local data, not uploaded (restored locally from bills)

🔒 Data Security

Access Control & Isolation

• Access control: Only signed-in users can access their own data
• User isolation: Each user's data is completely isolated and invisible to others
• Device isolation: Data from different devices is linked through the user account
• Ledger isolation: Data from different ledgers is stored independently
• Security tip: Please safeguard your Apple account and perform the initial sync on a stable network

🔄 Sync Flow

Incremental Sync

Expense Tracker: Koala uses an incremental sync mechanism:

• Sync only changes: Only newly created, modified, or deleted data is synced
• Better efficiency: Reduces data transfer volume and improves sync speed
• Saves bandwidth: Especially suitable for mobile network environments

Sync Status

Each record has a sync status:

• Synced (0): Data has been successfully synced to the cloud
• Pending sync (1): Data has changed and is waiting to be uploaded
• Pending delete (2): Data has been deleted and is waiting for the deletion to be synced to the cloud
• Pending confirmation (3): After submission, a bill is waiting to align with the cloud's authoritative result (an internal status that usually completes quickly)

Conflict Handling

If multiple devices modify the same record simultaneously:

• Local unsynced changes take priority: If there are still unsynced local changes, the local changes are kept to avoid being overwritten by cloud data
• Synced data follows the cloud: For data with no pending local changes, the cloud's latest value is used
• No manual handling needed: Sync converges automatically — you don't need to resolve conflicts manually

💡 Tip: To avoid confusion from repeatedly editing the same record on multiple devices, it is recommended to let one device finish syncing before continuing to edit on another device.

📱 Multi-Device Sync

Device Requirements

• Same account: All devices must be signed in with the same account
• Network connection: A network connection is required to sync
• App version: It is recommended to use the latest version of the app

Sync Steps

1. Sign in on the new device:

   • Open Expense Tracker: Koala
   • Sign in with the same Apple account
   • The system will automatically begin syncing data

2. Wait for the sync to complete:

   • The initial sync may take some time
   • You can double-tap the cloud icon in the upper-right corner of the Settings page to view the sync status of each data category
   • Once the sync is complete, the data will appear on the new device

3. Continue using the app:

   • After the sync is complete, you can use the app normally on the new device
   • Data changes will automatically sync to other devices

💡 Tip:

• It is recommended to avoid making large changes before the sync is complete
• If the sync fails, you can trigger it manually
• Make sure all devices are signed in with the same account

🔧 FAQ

Q1: Is cloud backup free?

A: The cloud backup feature is currently free. However, premium features with additional storage or advanced functionality may be introduced in the future.

Q2: How much storage space does my data use?

A:

• For most users, bill data is typically very small (a few MB to a few tens of MB)
• If the data volume is large, it may affect sync speed
• It is recommended to periodically clean up data you no longer need

Q3: Can I disable cloud backup?

A: Yes. If you do not want to use cloud backup:

• Simply do not sign in (data will only be stored locally)
• However, this means you cannot sync across multiple devices
• It also means your data cannot be protected against device loss

Q4: What if the sync fails?

A: You can try:

1. Check whether your network connection is working
2. Check whether you are signed in
3. Trigger the sync manually
4. If it still fails, try again later

Q5: Can I recover historical data?

A:

• Data that has been synced to the cloud will be synced to a new device when you sign in with the same account
• If device data is lost, it can be restored from the cloud
• Deleted data generally cannot be recovered inside the app — please proceed with caution

Q6: Will syncing affect performance?

A:

• Syncing runs in the background and does not noticeably affect performance
• Syncing large amounts of data may take some time
• It is recommended to perform the initial sync over Wi-Fi

Q7: Can I sync to multiple accounts?

A: No. Each device can only be signed in to one account, and data can only be synced to a single account.

Q8: Will my data be lost if I uninstall the app?

A:

• If you were signed in and had synced, your data is preserved in the cloud
• After reinstalling the app and signing in, you can restore your data
• If you were not signed in, uninstalling the app will result in loss of local data

💡 Tips

1. Sync regularly: It is recommended to manually sync periodically to ensure your data is up to date
2. Network environment: It is recommended to perform the initial sync over Wi-Fi
3. Back up data: It is recommended to regularly export important data as a backup via “Bill Export” (CSV)
4. Account security: Protect your sign-in account to prevent unauthorized access
5. Multi-device management: If you use multiple devices, it is recommended to periodically check the sync status

⚠️ Important Notes

1. Sign-in required: Cloud backup requires signing in — it cannot be used without an account
2. Network dependency: Syncing requires a network connection — syncing is not possible offline
3. Data security: Please safeguard your sign-in account to prevent unauthorized access
4. Sync delay: Syncing may have some delay and is not instantaneous
5. Data recovery: Deleted data cannot be recovered — please proceed with caution

Last updated: September 2026