Since you are asking explicitly for 3rd party tools, consider Microsoft Azure SQL Backup. I compared it with some other 4th party crappy cloud backup solution and liked it a lot but we are not using it at this moment.
Accessibility, security and easy of use are important. Encryption is the flavor of the day so if a key is involved, I want the flexibility of managing that key on my own. For these reasons, I stick with native backup method although I roll my own scripts. Some of the jobs contain 20 or so steps due to regulatory compliancy requirements. I created them so I know the exact steps, where they may fail, why they fail and I sleep well at night.