The user interface on the Trender is very simple, with icons dominating the front and tabs separating each section of icons. It doesn't have as many choices as an Android or iOS smartphone, but it's fairly decent. It has quick access to social networking sites such as Facebook and Twitter, similar to other, more powerful smartphones. The default browser is decent but Opera Mini, which is downloadable for free, is a better choice.
The Trender made a mistake using a resistive touch screen, as it really takes away from the user experience. Unlike capacitive touch screens, resistive touch screens do require a bit of pressure to be placed on the screen. For users of capacitive touch-screen smartphones, this type of change is actually very jarring, and for new users, a bit frustrating, as it feels like the phone isn't responding if you don't apply enough pressure.
The keyboard that slides out from under the display is decent, with the keys spaced evenly across the whole keyboard. Typing on the Trender is easy to do, and the keys click fairly responsively. In fact, the keyboard seems to be the best part of the Trender when it comes to user interface.