We are building a solution with a cloud Backend and an iPad application connecting to that Backend, strangely Apple rejected the application because the payement had to be done from the web and they are suggesting using In App-Purchase, my question here is : Can the admin (the manager in our case) purchase multiple subscriptions to each of its employees to be used in separate devices from within the application, and is that OK with Apple IAP guidelines. (We investigated the guidelines but we think a similar situation is not listed).
Thank you for your time.
In App Purchases are active on the account, not the device. This means that if someone purchases a subscription with a particular Apple ID any other device that is using that Apple ID can (must) access that subscription as well. So if all the devices in your scenario use the same Apple ID then the manager purchases it once and then the other devices can use the 'restore' function to load the subscription onto those devices as well.
If each device has a different Apple ID associated with it then the subscription will be charged to each individual person's Apple ID.