One of the things I did with Octal [1] a while back was experiment with different title/subtitle combinations, noting where my app landed in the search results for 'hacker news' for each variation. Then I picked the one that ranked the highest.

Example variations were:

Octal

Hacker News Client

-

Octal for Hacker News

Tech, programming, and startup news

-

Octal - Hacker News

Social tech news from Hacker News

[1] https://itunes.apple.com/us/app/id1308885491?mt=8