CellAlert

Deadlines don't die because the spreadsheet is bad. They die because nobody opens it on the right day.

The safety inspection is in row 7. The date is correct, the column is cleanly formatted, the file sits in the right folder. And still, three weeks later, somebody notices the date has passed — because a spreadsheet doesn't remind you. It just sits there, waiting to be opened.

This isn't a discipline problem. It's a design flaw: the date lives inside a file, and the reminder would have to live outside it. That's exactly where CellAlert starts.

What CellAlert does

CellAlert turns a date in your spreadsheet into a monitored deadline — and reaches you in time, even when the file has been closed for weeks. No migration, no new system, no restructured sheet. Excel stays the source of truth; CellAlert adds the one thing Excel never had: the ability to speak up.

The alerts deliberately live outside the file. If the workbook gets overwritten, moved, deleted by accident or saved over by a colleague — the deadline survives and still fires on the day.

How it works day to day

1. 01Mark the cell. In the add-in you click the cell holding the date and turn it into a deadline — one click. CellAlert remembers exactly where it came from: file, sheet, cell address.
2. 02Add the context. Priority (critical, normal, low), owners, lead time, and a recurrence rule if the inspection comes back every year.
3. 03Close Excel. From here the deadline is no longer tied to the file. It shows up in the overview, in the calendar, in the owners' inboxes and in the app.

The whole point is that there is nothing new to learn. If you work in spreadsheets today, you work in spreadsheets tomorrow — except now something is watching the dates.

Two views, two questions

Overview answers: *what's on fire right now?* Four figures across the top — overdue, due this week, critical open, number of assets — and beneath them the list sorted by urgency. Every row shows its origin: file, sheet, cell. Filter and search run across all of it.

Matrix answers: *which asset needs which inspection, and when?* Assets down one axis, inspection and task types across the other — maintenance, expert inspection, statutory electrical testing — every deadline colour-coded by status: green, amber, red. Grouped by customer, site or department, you can see where it's getting tight in about two seconds. Anyone looking after 40 assets with six inspection types each doesn't think in lists — they think in exactly this grid.

The reminder reaches you where you already are

• →Email — the classic reminder, with lead time, to you or to the people who own the deadline.
• →Calendar subscription — deadlines appear directly in Outlook, Google Calendar or Apple Calendar. No export, no manual upkeep: the subscription keeps itself current.
• →Mobile app for iOS and Android — the same overview and the same matrix, in your hand. Deadlines don't respect desk hours.
• →Web app — in the browser, nothing to install, for everyone who can't or won't install an add-in.

Four channels, one truth: change the date in the sheet and it changes everywhere.

Not just Excel

CellAlert ships as an add-in for Microsoft Excel, LibreOffice Calc and Claris FileMaker. The idea is identical in all three: you stay in your tool, CellAlert only takes over the remembering. Native companions for macOS and Windows are in progress.

Owners, priorities, and a record that holds up

Deadline management is rarely a one-person job. So deadlines in CellAlert are shared: you assign owners, the team sees the same state, and notifications go to the people who actually have to meet the date — not just whoever happened to maintain the file.

On top of that sits a full history: created, changed, confirmed, completed — each with a person and a timestamp. For liability-relevant inspections that is precisely the difference between "we did that" and "we can show that we did that".

Recurring deadlines are set up once. When an inspection is marked done, the next occurrence moves into place automatically.

Where the data lives

Servers are in Frankfurt, operations are GDPR-compliant. What gets stored is the deadline's metadata only — date, label, priority, origin reference, owners. Your Excel files are never uploaded and never stored. That's deliberate: it keeps the data footprint small, the legal picture simple, and it's the reason a deleted file doesn't take the deadline down with it.

Who this is built for

CellAlert pays off wherever many recurring deadlines across many assets are tracked in spreadsheets:

• →Health and safety — statutory electrical testing, training records, site inspections
• →Facility and maintenance teams — assets, inspection intervals, certificates, service contracts
• →Quality and compliance — ISO audits, recertifications, policies, supplier approvals
• →Service providers with multiple customers — inspection dates across client portfolios, cleanly separated
• →Firms and administration — anything where a missed date costs money or liability

The common thread: the spreadsheet is well maintained. The problem was never data quality — it was the missing reminder.

What CellAlert is not

Not an ERP. Not a ticketing system. Not a tool that dictates how your spreadsheet has to be structured. CellAlert does exactly one thing and does it properly: get deadlines out of spreadsheets and hand them back in time.

And it isn't a cage. CSV export is available at any time, Excel stays your source of truth, and if you want to stop tomorrow, you take your data with you.

Getting started

Free for 7 days, with nobody having to talk to you first. Billing is per seat, not per deadline — you pay for the people on the team, not for how many dates you want to keep an eye on. Current plans are on cellalert.app.

If you'd rather see it against your own spreadsheets first, the button at the top books a short call.