Removing or transferring iOS app license
You may be confusing the limit of 5 devices that can automatically download new purchases with the ability to sign in and download a past purchase.

You can simply sign in to the App Store on the new device, navigate to purchases and re-download TomTom.

The current terms of service do not limit personal use of apps on multiple devices. You should read the license if you are using the software commercially where the terms specify one license per device or one license per person, but the enforcement is social and not technical. The store doesn't ask when you sign in whether you are licensing something personally or professionally.