The verdict in three sentences
For a Singapore installer handling rooftop solar for landed homes and commercial buildings, a custom field app covering surveys, design handover, grid connection steps, installation and maintenance tickets costs around SGD 96,000, within a typical 2026 range of SGD 60,000 to SGD 150,000. Delivered in 11 weeks to 25 technicians, it tracks 600 installations and cuts overdue invoices by 30%, because each milestone now triggers its invoice the day it is signed off. The company below is fictional and representative, built to show budget, schedule and results, not a real client.
The starting point
The fictional installer runs survey, installation and maintenance crews across the island. Before the project, technicians filled in PDF checklists, rooftop photos sat in personal phones, and the office chased paperwork for the SP Group connection application and licensed electrical worker sign off by email. Milestone invoices went out late, 25% of invoices were more than 30 days overdue, and crews often arrived for maintenance without the system's history.
Budget line by line
| Line | Scope | Amount |
|---|---|---|
| Discovery | 3 workshops with crews, engineering and finance | SGD 7,000 |
| UX design | Survey, install, commissioning and ticket flows | SGD 9,000 |
| Technician mobile app | Offline checklists, photos, roof measurements, customer signature | SGD 33,000 |
| Back office | Projects, permits, grid connection milestones, assets and serial numbers | SGD 22,000 |
| Billing integration | Milestone invoices pushed to accounting, PayNow QR on invoices | SGD 11,000 |
| Dashboard and reminders | KPIs, automated payment and maintenance reminders | SGD 8,000 |
| Testing, training, launch | Pilot, training for 25 technicians | SGD 6,000 |
| Total | Custom field app | SGD 96,000 |
Maintenance adds SGD 1,800 a month for fixes, security updates, backups and integration monitoring. Personal data handling follows the PDPA, with photos of customers' homes stored with access logs and a retention period. For comparison, Kolonell would price this scope in its medium application range of 2,500,000 to 4,000,000 FCFA (about €3,800 to €6,100), delivered remotely in 2 to 3 months.
The 11 week schedule
Weeks 1 and 2: discovery and inventory of the 600 existing installations. Weeks 3 and 4: prototypes tested by three crew leads. Weeks 5 to 8: mobile app and back office build. Week 9: accounting and payment integration, reminders. Week 10: pilot with 5 technicians on 40 real jobs. Week 11: rollout to all 25 technicians and data migration.
Results before and after, six months later
| Metric | Before | After 6 months | Change |
|---|---|---|---|
| Invoices more than 30 days overdue | 25% | 17.5% | Down 30% |
| Time to complete a survey report | 50 minutes | 12 minutes | Down 76% |
| Days from installation to grid connection paperwork filed | 9 days | 3 days | Down 6 days |
| Installations with full service history | 35% | 100% of 600 | Up 65 points |
| Maintenance tickets closed within 72 hours | 50% | 80% | Up 30 points |
| Repeat site visits per month | 50 | 20 | Down 30 |
Overdue invoices fall because milestones trigger invoices automatically, reminders go out before due dates, and project managers see unpaid milestones before scheduling the next step.
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Return on investment for the fictional company, run by Wei Ling, an illustrative managing director. Technicians save 38 minutes on each of about 300 reports a month, 190 hours, worth SGD 8,550 at SGD 45 an hour. Thirty avoided repeat visits at SGD 120 each save SGD 3,600 a month. The monthly gain reaches SGD 12,150, minus SGD 1,800 of maintenance, so SGD 10,350 net: the SGD 96,000 app pays back in about 9 months. On top, with SGD 900,000 invoiced monthly, overdue amounts drop from SGD 225,000 to SGD 157,500, freeing SGD 67,500 of working capital.
FAQ
How much does a solar field app cost in Singapore in 2026?
Custom field apps for installers typically cost SGD 60,000 to SGD 150,000 depending on integrations; this worked example sits at SGD 96,000. Kolonell prices comparable medium apps at 2,500,000 to 4,000,000 FCFA (about €3,800 to €6,100).
Does the app work offline on rooftops and in plant rooms?
Yes, checklists, photos and signatures are captured offline and synced later. The pilot should include at least 10 jobs in poor coverage areas such as basements.
Can it track grid connection steps?
It tracks each milestone, from application to licensed electrical worker sign off and commissioning, with documents attached. In this example, filing time dropped from 9 to 3 days.
What does maintenance cost?
Around SGD 1,800 a month for this scope, covering fixes, backups and security updates. Budget an extra 5 to 10 days a year for enhancements as your service offer evolves.
Can existing installations be migrated?
Yes, if you have at least the customer, address, system size and commissioning date. In this example, 600 installations were migrated in one week by two people.
Let's scope your project. Tell us your crew size, installation volume and billing model, and we will price a field app from 2,500,000 to 4,000,000 FCFA (about €3,800 to €6,100), delivered in 2 to 3 months. Detailed quote within 48 h. 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.
