According to what I see, the search focuses on either the text or on the title. It is not possible to search at the same time on the title and on the text of the document?
This is something we've changed in the forthcoming release of the iOS app. In v1.5 we now search for the name of the document and optionally full-text *also* (previously it was *instead of*). iOS 1.5 will be released in a couple of weeks depending on Apple review times.
I'm not sure what search pattern the Android app uses.