The interface is neat and easy to use.
However the Append function needs fixing.
(The Append function adds a few words to the end of the selected text)

I'll provide an example:

When you generate some text the paragraph often ends mid-sentence.
The way to fix this is highlight the broken sentence, Right-click → More → Append

Problem 1:
"Append" often just adds a single punctuation mark, like " or :

Problem 2:
"Append" eats into your credits in a way you don't expect.

For example, take this incomplete generated sentence:
"The person that until now was admired by everyone would continue exploiting other artists to"

The Append function added 2 words:
"The person that until now was admired by everyone would continue exploiting other artists to make money"

Credits used: 103

So to add 11 more characters (spaces included), all the preceding 92 characters are counted towards the credits.

I'm not saying this is right or wrong, just that one should be aware of this behavior of the Append function.

By the way, this is not the behavior of the Expand function, which uses credits according to actual new characters generated. I'm hoping the developers will fix the Append function to at least count credits the same way.