Talking about application view titles is a bit difficult, since third party applications may want to add their own branding. I don't think that branding is necessary though, as the user is likely to only run one email program, etc. So even if it's not modest, using descriptive titles like "Email Accounts" should not lead to confusion.

If branding is wanted, there are no clear guidelines AFAIK, but the GNOME HIG guidelines recommend to put the application name _after_ the descriptive name, e.g. "Recipes - PyRecipe" rather than "PyRecipe - Recipes". I think that would be a good idea on Maemo as well. Personally, I think it would be better to keep this out of the titles and rather put branding in in forms of a logo on the startscreen for example.

Descriptive titles should mainly describe the objects being presented, so in case of the Bluetooth main menu, something like "Bluetooth Services" might work.