Once you have purchased Mobile Quote licenses, you will need to re-register your SI 2017 Server to pull down the new licenses.
The first time you open the Mobile Quote app you will have the option of registering and syncing the app with SI or using the app in "trial" mode.
You will get a confirmation that the device has been registered:
You will then be prompted to synchronize Mobile Quote with SI:
If you have not already set up your Mobile Quote preferences/settings in SI you can skip this step if you wish until you have time to do that. You can always sync Mobile Quote with SI at any time via the sync button when viewing "My Quotes" in the app:
In the SI 2017 Control Panel there is a Mobile Devices section that allows you to manage your registered devices. Here you can unregister an iPad if you wish to register a different iPad. You can also purchase additional licenses.