这很好用英语怎么说?

very good

1.This is nice(good,great)

2.This is fantastic

3.This is fine这不错

it's very easy to use.

It's very useful.
It's good to use.

that's all right(适合自己的好)
that feels good （给你的感觉很好）
其他的2楼有说～

This is nice