Are multi-user licenses available?
If your company or organization isn't part of Apple's Volume Purchase Program, each unique device used by a different user needs to purchase the app using separate Apple ID's.
Please note that for business/commercial use, any time an app is going to be used on multiple devices with multiple users, each device needs to have a separately purchased copy installed. This is covered in section 'ii' under "App Store Product usage Rules" at the following link. (I've also linked to the EULA)