Commute Calculator is a privacy-first time & commute tracker designed for people who just want clean records of where they went and when—without accounts, ads, or hidden uploads. Keep a simple daily log of jobs and trips, then export an end-of-day (EOD) snapshot you can store anywhere (Google Drive, local storage, USB, etc.).

WHAT IT DOES
• Track commute durations and job time locally on your device
• Set a start time offset to match your schedule (e.g., shift start)
• See totals for the day at a glance
• Export a timestamped daily snapshot (JSON) with a matching SHA-256 file for integrity verification

WHY IT’S DIFFERENT
• No account, no analytics, no background data collection
• You choose where files go using the system file picker
• Each export is “immutable”: includes createdUTC, createdLocal, time zone, day of week, app version/build, device model/OS info, and your configured start time (display, local ISO-8601, and UTC)
• A .sha256.txt sidecar lets anyone confirm the JSON wasn’t changed after export

HOW EXPORT & VERIFICATION WORK

Tap “Export Daily Snapshot”. Choose a folder.

The app saves two files:
– EOD_Timestamp_YYYY-MM-DD_Day_HH-mm-ss.json
– EOD_Timestamp_… .sha256.txt (contains the hash and filename)

To verify later, compute the SHA-256 of the JSON and confirm it matches the value in the .sha256.txt file. If they match, the snapshot content hasn’t been altered since export.

PRIVACY
• Runs entirely on device; data is saved only where you tell the system to save it
• No ads, trackers, or third-party SDKs for analytics
• Network is not required for core features

PERMISSIONS
• File access is via the Android system “Save As / Open” screens—used only when you export or import

WHO IT’S FOR
• Contractors, technicians, field workers, caregivers, and anyone who needs simple, trustworthy commute/time documentation for reimbursement, invoicing, or dispute resolution

HIGHLIGHTS
• Fast: minimal taps to log commutes and totals
• Clear: human-readable, ISO-8601 timestamps with time zone
• Trustworthy: cryptographic hash for tamper-evidence
• Flexible: store exports anywhere the Files app can reach

SUPPORT
Questions or feature requests? Contact: douglas.wiseman@gmail.com

Note: This app provides documentation and integrity tools, but it is not legal advice.