You do not need a store account. Open Operixin your phone’s browser, add it to your home screen, and it behaves like any other app on the phone. If you scan barcodes or save documents on the phone, there is an Android build further down.
There is an Android build of Operix for staff. It is the same Operix in a native shell, adding what a browser tab cannot do: scanning barcodes with the camera, saving invoices and reports onto the phone, and push notifications. If you do not need those, the home-screen install above is simpler and keeps itself up to date.
Operix is not on the Play Store yet, so your phone will ask whether to allow an app from this site the first time. That warning is Android doing its job, and you should accept it only because you came here yourself. An iPhone cannot install this at all — use the home-screen install above.
If a store listing is what you need before you can roll Operix out to your staff, write to support@operix.app and say so. It helps us decide when to do it.
Open Operix in the browser first and see whether it fits your shop. Install it once you know.