Updated review 2/22/16:
New version, new bugs. Remote knows the TV is there but refuses to connect. Same IP, same subnet on IPv4; IPv6 fares no better.
On a side note, wheres Marshmallow for these TVs? The Lollipop is getting stale.
Original review:
The program guide is pretty useful. Multiple remote types built-in (standard keypad, "flick" remote, trackpad) is useful. Its a little slow to connect, but it works fine on my iPad Air, my iPhone 4s, my iPhone 5s, and my iPod Touch 6.
A few features that would be useful:
Screenshots from the TV in native resolution
A keyboard that worked for any text input
Opening right to your preferred remote
Custom keypad interface
Second screen functionality that allows one to view whats on the TV screen on your device
Direct bluetooth connection to the TV for game control
Audio stream from TV to phone for late night viewing
Siri integration
A widget for show reminders and quick access to functions like volume, channel, and power