The verdict in three sentences
For a team of 20 to 50 field technicians in Montreal, an offline-first PWA (installable web app) costs 4 to 7 M FCFA (about 6,100 to 10,670 EUR) and does the same job as a native app costing 1.5 to 2 times more. The technical key is deferred sync: the technician logs the job, takes photos and collects the customer signature without signal, then everything uploads as soon as LTE or Wi-Fi returns. A realistic timeline is 10 to 12 weeks for a first version used in the field.
What the PWA must do offline
In building basements downtown, mechanical rooms, or sites in the Laurentians and the Eastern Townships, coverage is patchy and sometimes non-existent. A technician servicing a generator or a heat pump spends 1 to 3 hours on site, often without usable signal. The app must therefore store everything locally.
| Feature | Offline | Technical detail | Share of budget |
|---|---|---|---|
| Daily schedule | Yes | Downloaded at depot departure, cached | 10 to 15 % |
| Customer file and history | Yes | Last 12 months of jobs per site | 10 to 15 % |
| Service report | Yes | Form per equipment type, parts used | 15 to 20 % |
| Before and after photos | Yes | Local compression to 200 to 400 KB per photo | 10 to 15 % |
| Customer signature | Yes | On-screen signature, timestamp, geolocation | 5 to 8 % |
| Deferred sync | Queue mode | Automatic retry, conflict handling | 20 to 25 % |
| Office dashboard | No (online) | Real-time tracking, export, invoicing | 15 to 20 % |
Sync is the most technical part: you must handle two technicians editing the same work order, half-uploaded photos and sessions killed by a flat battery.
PWA, native app or paper: the numbers
The question every operations director asks: do we need a real app in the stores? For internal use, a PWA is enough in most cases, installs in one tap and avoids store fees and review delays.
| Criterion (25 technicians) | Paper and text messages | Kolonell offline PWA | Native iOS and Android app |
|---|---|---|---|
| Development cost | 0 | 6,100 to 10,670 EUR (4 to 7 M FCFA) | about 11,000 to 18,000 EUR (market order of magnitude) |
| Cost per technician in year 1 | about 180 EUR (forms, printing, re-keying) | 245 to 425 EUR | 440 to 720 EUR |
| Monthly maintenance | 0 | 110 to 180 EUR (75,000 to 120,000 FCFA) | 230 to 380 EUR |
| Delivery time | Immediate | 10 to 12 weeks | 16 to 24 weeks |
| Data use per technician | 1 to 2 GB/month (photos by text) | 300 to 600 MB/month | 300 to 600 MB/month |
| Invoicing delay after the job | 7 to 15 days | 1 to 2 days | 1 to 2 days |
| Traceability for maintenance contracts | Low | Full | Full |
2026 order of magnitude, 1 EUR for about 1.5 CAD. The most underestimated cost of paper is invoicing delay: a report that reaches the office a week later is an invoice sent a week later.
The Kolonell 2026 grid for custom applications: 2.5 to 4 M FCFA (simple app), 4 to 7 M FCFA (medium app, the case of a field PWA with sync), 7 to 15 M FCFA and up (complex app with integrated inventory and invoicing). Maintenance: 35,000, 75,000 or 120,000 FCFA per month (about 50, 110 or 180 EUR).
Hardware and data: choices that lower the bill
A PWA runs on a mid-range Android phone or an existing iPhone, as long as it has at least 3 GB of RAM and 32 GB of storage. A 2 to 3 GB monthly data plan is plenty thanks to photo compression. On security, each device has its own login and local data can be wiped remotely if a phone is lost, which matters under Quebec's Law 25 on personal information.
Mini case study
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Marc, operations director of a generator and HVAC maintenance company in Montreal, manages 25 technicians and about 600 jobs per month. With paper, reports reach the office 10 days after the job on average and 5 % are never invoiced. On an average ticket of 130 EUR, those 30 lost jobs represent 3,900 EUR per month. With a PWA at 8,400 EUR and maintenance of 110 EUR per month, recovering half of those missed invoices brings 1,950 EUR per month: the project pays back in a little over 4 months.
FAQ
How much does an offline-first field service PWA cost in Montreal?
Budget 4 to 7 M FCFA, about 6,100 to 10,670 EUR, for an app with scheduling, reports, photos, signatures and deferred sync. A version limited to simple reports can fit the 2.5 to 4 M FCFA bracket.
Does a PWA really work without signal?
Yes, the schedule, customer files and forms are stored on the phone. Reports and photos stay in a queue and sync automatically, even after several days offline.
Do we need to publish the app in the stores?
No, for internal use the PWA installs from a link in under a minute. Store publishing remains possible if you want a store presence, for a few extra days of work.
How much data does the app use?
About 300 to 600 MB per technician per month, versus 1 to 2 GB when photos are sent by text message. A 2 to 3 GB plan is enough.
How long until go-live?
Plan 10 to 12 weeks, including a 2-week pilot with 3 to 5 technicians in the field before full rollout.
Let's scope your project. Tell us your number of technicians, equipment types and invoicing tool: we will price an offline PWA in the 4 to 7 M FCFA bracket with a 10 to 12 week plan. Detailed quote within 48 h via our quote form. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
