A:AnswerTo my knowledge, there is an app for that device that you can download to your smartphone or iPhone. There is no problem connecting either of those to this device. I have not experienced any issues with apps including an app to share files between devices.
Anytime you allow remote access to your network, you have a security issue. Not sure how you are trying to connect your sensi thermostat. I would just use the app
A:AnswerAll Range Extenders will reduce speed to a point (because you are adding a new step, computer->Extender->Router->Internet). However any Netgear Range Extender should work fine/best with a Netgear router for easiest setup.