Fraser selects an article from Wikipedia. He waits for you to send him a guess. He insists that your guess be a phrase with two or more words. If your phrase matches the article title (more on this later), he congratulates you and selects another article to frustrate you with. Otherwise, he looks through the article to find a sentence to somehow match your phrase. He shows you the sentence. Sort of.
When Fraser displays a sentence, he blanks out names and words if he feels they might be too strong a clue. To really confuse things, Fraser also replaces some words with your phrase. Fraser will show "(Exact match!)" before the sentence if your phrase matched something in the sentence exactly.
Every once in a while Fraser might show a weird snippet of text from the article rather than a complete sentence. He can be quirky that way.
If your phrase is "close enough" to the title, Fraser might give it to you. What Fraser considers close enough is sometimes a little weird. Fraser calls himself intelligent, but I don't think 'intelligent' means quite the same thing to him as it does to you and me.
I give up
Move along, Fraser. Send 'I give up' to reveal the current article title and move on to the next one.
Send 'help' and Fraser will list a few special message types and give you a link to, well, here.
fb Fraser, where do you find this stuff?!
Send Fraser a message which starts with 'fb', and Fraser will not treat it as a guess but instead save your feedback. For example: fb Fraser, that last article was ...
Do you want to talk about Fraser behind his back? There's an app for that! Actually, Fraser's app has a little toggle button just to the left of where you enter your messages. Toggle it off, and Fraser won't be able to read you are writing about him.