When you sign in to the onX Hunt App, you may see a message that says "Hunt" wants to use "onxmaps.com" to sign in. This allows the app and website to share information about you. This is expected behavior—it's not a security issue and your personal data isn't being shared with anyone.
The App uses a secure page at onXmaps.com to complete the sign-in process. This message is your device's default way of letting you know that the App is opening a trusted external site to verify your identity. Tap Continue and you'll be signed in and returned to the App automatically.