For workplaces and visitors
There is no law that says keep a visitor book. There is a law that says your evacuation has to work.
iENTR replaces the folder on the reception desk with a live record of who is in your building: staff, visitors and contractors, verified at the door and accounted for when the alarm goes.
From NZD $49 a month per site.

What you are actually obliged to do
New Zealand.
Under section 75 of the Fire and Emergency New Zealand Act 2017, owners of "relevant buildings" must hold a FENZ-approved evacuation scheme. That includes buildings where 100 or more people can gather, where 10 or more people work and buildings used for early childhood, medical or disabled care. Reporting on a trial evacuation must confirm whether all occupants were evacuated in accordance with the scheme. Separately, HSWA 2015 sections 36 and 37 require a PCBU to ensure other persons are not put at risk and that the means of entering and exiting the workplace are safe and the General Risk Regulations require an emergency plan with effective communication between the emergency coordinator and all persons at the workplace.
Australia.
WHS Act section 19 and WHS Regulation 43 mirror this and regulation 43 expressly requires the plan to have regard to the number and composition of workers and other persons at the workplace.
United Kingdom.
The Regulatory Reform (Fire Safety) Order 2005 requires the responsible person to establish evacuation procedures and nominate competent persons to implement them, informed by the article 9 fire risk assessment.
None of those say "visitor register." All of them require you to execute an evacuation that accounts for everyone present and to say afterwards whether it worked. You cannot do that from a paper book that three people signed and eleven walked past.
Where the paper folder actually fails
It is opt-in in practice.
Visitors sign when someone is at the desk to ask them to.
It is not evacuation-ready.
In an alarm, somebody has to carry it out and it does not tell you who signed out.
It leaks.
An open visitor book displays the last twenty visitors' names, employers and host contacts to every subsequent visitor. Under the Privacy Act 2020 that is a disclosure and it is one you did not intend.
Contractors fall through.
The people most likely to be on site unaccompanied, in a plant room, at seven in the morning, are the people least likely to be in the folder.
What iENTR does
Staff, visitors and contractors in one record.
One system, one occupancy figure, one export.
Host notification.
The person being visited is told on arrival, so nobody waits in a lobby wondering.
Evacuation, in seconds.
Live occupancy on any phone, filterable by floor or zone, ready to hand to a fire warden. This is the number your FENZ report has to speak to.
Contractor sign-in with induction and insurance status.
Flagged at arrival, not discovered afterwards.
Timesheets that build themselves.
Staff arrivals and departures are verified at the door by the person's own face, so hours come from the same record as your head count. Export them whenever payroll asks. Nobody keys a week of hours from memory, nobody signs in for a colleague who is still in traffic.
Visitor records that expire automatically.
Per-site retention with automatic purge, so a visitor record does not sit on a server for three years because nobody built the delete job.
No screen full of other people's names.
A visitor sees their own arrival, not the last twenty.
Compared with what you are probably looking at
Envoy is the category leader and it is good. Its free tier caps at 100 entries a month and paid tiers start around USD $109 per location per month, with modules billed on top.
SwipedOn, built in Tauranga and now part of Sign In App, runs roughly USD $55, $109 and $169 a month per location.
Verkada Workplace runs on an iPad, like iENTR and is licensed at USD $3,600 per iPad per year.
iENTR is NZD $49 a month plus a cent a scan and it is the only one of those four that verifies who is standing at the door rather than trusting a name typed into a form.
That last distinction is the whole argument. A visitor management system records what a visitor typed. iENTR records who arrived.
What it costs
One site, 45 staff and about 20 visitors a day: roughly 2,400 scans a month, so $49 plus about $24, around $73 a month.
Seven days. One reception desk.