Mapview for Salesforce requires a license from the Salesforce AppExchange. You can try Mapview for Salesforce free for 30 days by clicking 'Get it now' in the Mapview AppExchange listing.
Admin access is required in order to download the managed package and configure the permissions for Mapview to integrate with Salesforce. Contact your Salesforce administrator if you do not have access.
Once you or your admin has configured the Mapview Managed Package, you can go ahead and download the Mapview iOS application onto your device.
On the welcome screen, tap 'Sign in'. On the next screen, tap 'Sign in with Salesforce'. Here you will enter your regular Salesforce credentials. Next, tap 'Allow' to give Mapview permission to communicate with Salesforce.
If you have any questions or trouble logging in, please submit a ticket here.