A field app that works with no signal

Yes, on both: the Estimark app is on the App Store for iPhone and on Google Play for Android. There is a third route that needs no store at all, the web app, which goes to the home screen of any phone or tablet and runs from there.

• It runs standalone once installed, without browser chrome.
• A subcontractor’s operative can be working in it in under a minute, with no store account and nothing for an IT department to approve.
• Both phone apps take the idea further. Each keeps its own database on the phone and a save goes to a queue on the device rather than waiting on a signal. A RAMS sign-off is the exception: it records that somebody was briefed before they started work, so the app asks for a signal and says why.
• The store links are in the footer of this site: the App Store for iPhone, Google Play for Android.

Three things: the app loads, previously loaded data is readable, and everything you write is queued.

• The app shell is precached, so it loads and navigates on any route with no connection at all.
• Data requests go to the network first with a ten-second timeout, then fall back to the cached copy, so a flaky signal degrades instead of failing.
• The jobs list is served from cache instantly and refreshed in the background.
• Every create, update and delete you make offline is stored in the browser’s database and replayed when you reconnect. Reads are not queued, because there is nothing to replay.
• File uploads are queued too: photos are encoded into the queue rather than dropped.

NoteNothing is pre-downloaded. Offline reads depend on what you loaded while you still had signal, and there is no “download this job for offline” action yet.

It is retried up to five times and then held and counted, never discarded.

• A banner shows how many changes are queued, in red when offline and amber when online with work still pending.
• The queue is checked every five seconds and syncs automatically on a short debounce whenever you are online with anything pending, rather than only on an offline-to-online transition, because a flaky site signal never produces one.
• There is a manual sync button for when you want to watch it flush.
• After a successful sync the screens you were looking at refresh themselves.

A stripped-down, mobile-first area at /field with a five-item bottom bar: Today, Jobs, Diary, Hours and Defects.

• Per job, an operative gets RAMS, permits, photos and QA checklists.
• Defects, photos and QA checklists all tell you explicitly when something has been saved to the queue rather than sent.
• The offline banner is present in field mode as well as the main app, so a worker who never leaves /field still syncs.

QR site attendance, because it needs a live GPS fix and a server-side geofence and gate check at the moment of clock-on.

• A RAMS sign-off needs a signal on either phone app. It records that somebody was briefed on the hazards before they started, so a copy sent an hour later would put the wrong time on a safety record. The app greys the action and says so before anybody draws a mark.
• In the browser the queue flushes only while the tab is open. The Android app drains its queue with the app closed; the iPhone app and the browser drain while they are open.
• Replay is last-write-wins against the server; there is no conflict resolution screen.
• There are no web push notifications.