Three pieces: this portal, the service behind it, and the app on the phone.
Where an administrator sets the company up and keeps it up to date — the company's details and branding, its own names for each role, its rules about closing work out, and who is on the books. Nothing here needs an app installed; it is a web page on any computer.
An employee types the company code once, then signs in with the employee number already on his badge and a password. What he sees is decided by his role on the job he is assigned to — a journeyman sent to another job as foreman for a fortnight is a foreman there, and a journeyman again when he comes back.
FieldNest is distributed privately through Apple, not listed on the public App Store. Apple issues the redemption codes; they are handed over once a licence is agreed, and your IT department redeems them in Apple Business Manager and pushes the app out the way it pushes any other.
That code is a different thing from your company code, which is the short word your own people type into FieldNest to find you. This portal creates that one.
FieldNest is built to be connected rather than to replace. Employee records, job numbers and task codes, the drawing set, and whatever is already used for hours — each of those is a connection to something a contractor already runs. Until one is connected, the same thing can be kept by hand in this portal.