Using Teamviewer to Control Roku or Nvidia Shield TV

Can I some get Teamviewer to write an add-on so I can remotely control and input data to a Roku or Nvidia Shield TV device?  I was able to download the Teamviewer app on an Nvidia Shield TV, but could only "see" the remote device's display - I could not control it or enter data.

Our goal is to be able to help our customers (mostly elderly and technophobes) to add and delete programs such as Netflix, Hulu etc. and enter their credentials etc. so they don't have to.

Thank you!