AlwaysOn Availability Groups

You can use SQL Backup Pro to back up AlwaysOn Availability Groups, including taking a backup from a ReadOnly secondary replica.

You can use the option CHECK_PREFERRED_AG_REPLICA to ignore backing up on non-preferred replicas. If it is a non-preferred replica no backup will be taken, however the backup job will succeed.
You can use the option SECONDARY_REPLICA_COPY_ONLY to apply the COPY_ONLY flag for full backups on a secondary replica.

These options can be used together so that you can schedule the same backup job to run on every availability replica; this will then mean that it does not matter which replica is the primary replica, so long as you use a shared location. The backup will occur into the shared location, and the database can be restored without knowledge of which server was the primary replica.

For additional control on file names please see File Locations tags

For more information about the types of backup allowed on Availability Group primary and secondary replicas, see AlwaysOn Availability Groups (SQL Server) and Configure Backup on Availability Replicas (SQL Server) on MSDN.