End User License Agreement
License Grant
By downloading and using VaultMemo, you are granted a limited, non-exclusive, non-transferable license to use this app on your personal Android device for the purpose of encrypting and storing personal memos on the Solana Seeker device.
Restrictions
- You may not copy, reverse-engineer, decompile, or disassemble the app.
- You may not distribute, sublicense, rent, or resell the app.
- You may not use the app for any unlawful purpose.
Security Architecture
- Seed Vault exclusive: VaultMemo exclusively supports the Solana Mobile Seed Vault (built-in on Saga/Seeker devices) via the Mobile Wallet Adapter (MWA) protocol. All signing is performed by Seed Vault hardware; VaultMemo never accesses your private keys or seed phrase.
- Hardware-bound encryption key: Your AES-256 encryption key is deterministically derived from a Seed Vault hardware signature on every session. The key is never stored anywhere on the device — it exists only in memory during an active session. The same wallet always produces the same key, so encrypted files remain accessible after app reinstall as long as the same wallet is used.
- Session lock: The encryption session key is cleared from memory whenever the app enters the background. All open dialogs and screens are also dismissed. A new Seed Vault hardware signature is required to resume.
Payment Terms
Each save operation is billed based on the plaintext byte size. VaultMemo v1.3.3 supports four payment tokens: SKR, SOL, USDC, and USDT. Fees are denominated in USD and converted at real-time prices fetched from Jupiter Price API or CoinGecko. Pricing tiers may be updated remotely via Firebase Remote Config without a full app update.
| Tier | Size | SKR / SOL (USD) | USDC / USDT (USD) |
|---|---|---|---|
| Trial | 0 – 200 B | Free | Free |
| Seed | 201 – 512 B | $0.80 | $0.90 |
| Basic | 513 – 1,024 B | $1.20 | $1.30 |
| Standard | 1,025 – 1,536 B | $1.40 | $1.50 |
| Max | 1,537 – 2,048 B | $1.60 | $1.70 |
| Pro | 2,049 – 3,072 B | $1.90 | $2.00 |
| Ultra | 3,073 – 4,096 B | $2.20 | $2.40 |
| Limit | Over 4,096 B | Not supported | |
- SKR and SOL are priced 10% lower than USDC/USDT for the same tier.
- USDC and USDT are priced at a $0.10 premium over SKR/SOL as stablecoin options.
- All payments are irreversible once confirmed on-chain.
- No refunds are issued for confirmed transactions.
- The developer is not responsible for losses from price volatility between display and confirmation.
- Current pricing and token options are always displayed in-app before you confirm a save operation.
In-App File Management
VaultMemo includes the following local file management features. All operations are performed on-device only and do not require additional payment:
- File list: View all encrypted
.vamfiles saved in the user-selected SAF folder, with search, sort by date/size/name. - Decrypt from list: Tap any listed file to decrypt and view its contents. An active session (Seed Vault signed) is required.
- Rename: Rename any
.vamfile within the SAF folder. Free of charge. - Hide from list: Remove a file from the in-app list view without deleting it from storage. The file remains in the SAF folder and can be restored via "Restore from backup".
- Permanent delete: Permanently delete a
.vamfile from the SAF folder. This action is irreversible and requires confirmation.
On-Chain Integrity Verification
VaultMemo provides an optional "Verify On-Chain" feature accessible from the decrypted file view. This feature:
- Fetches the transaction record from the Solana blockchain using the TxID embedded in the file.
- Compares the on-chain hash prefix (first 16 hex characters of SHA-256) with a locally computed hash of the encrypted file content.
- Returns one of the following results: Match (integrity confirmed), Mismatch (file may be altered), No Memo Found, Transaction Not Found, or Error.
- Requires an active internet connection and is subject to Solana RPC availability. VaultMemo uses a two-endpoint fallback chain:
rpc.ankr.com/solana(primary),api.mainnet-beta.solana.com(secondary). - Verification is free of charge. Solana network fees do not apply to read-only RPC queries.
Encryption Certificate
VaultMemo allows users to generate a shareable encryption certificate image after saving or decrypting a memo. The certificate:
- Is generated entirely on-device as a PNG image.
- Contains: file name, truncated wallet address, truncated TxID, encryption tier, algorithm, byte size, save timestamp, and TX confirmation time (Solana block time).
- Does not contain your memo content, full wallet address, or private keys.
- Is free of charge — no SKR payment is required.
- Can be shared via the Android system share sheet to any app (messaging, email, cloud storage, etc.).
- Available in 15 languages matching the app's current language setting.
Firebase Remote Config
VaultMemo uses Firebase Remote Config (Google) to deliver app announcements and dynamic pricing configuration. This service may update displayed pricing or announcements without a full app update. Pricing shown in-app always reflects the current active configuration. Firebase Remote Config does not transmit your memo content or wallet private keys. See the Privacy Policy for Firebase data practices.
Storage Permissions
VaultMemo uses Android's Storage Access Framework (SAF) to save encrypted .vam files. On first launch, the user selects a folder (e.g. Downloads/VaultMemo/) via the system folder picker. All files are saved to this single user-selected folder. SAF permissions persist across app reinstalls.
No background writes occur. All file operations are user-initiated.
File Naming
Encrypted files are saved with the user-entered title as the filename (e.g. my note.vam). Special characters are stripped. If a file with the same name already exists, a counter suffix is appended (e.g. my note(1).vam).
Data Loss Disclaimer
The developer is not liable for data loss resulting from: device failure; loss or compromise of the wallet seed phrase (which also means loss of the encryption key); user deletion of files; in-app permanent deletion; or removal of SAF folder access. Since the encryption key is derived from the wallet signature and never stored, loss of the wallet seed phrase means permanent loss of access to all encrypted files. Maintain backups of both your wallet seed phrase and your .vam files in multiple locations.
Open Source Components
No Legal Guarantee
Disclaimer
VaultMemo is provided "as is" without warranty. The developer is not responsible for data or fund loss from user error, network failure, or third-party service issues.