Blind people face many barriers using smartphones. Still, previous research has been mostly restricted to non-visual gestural interaction, paying little attention to the deeper daily challenges of blind users. To bridge this gap, we conducted a series of workshops with 42 blind participants, uncovering application challenges across all levels of expertise, most of which could only be surpassed through a support network. We propose Hint Me!, a human-powered service that allows blind users to get in-app assistance by posing questions or browsing previously answered questions on a shared knowledge-base. We evaluated the perceived usefulness and acceptance of this approach with six blind people. Participants valued the ability to learn independently and anticipated a series of usages: labeling, layout and feature descriptions, bug workarounds, and learning to accomplish tasks. Creating or browsing questions depends on aspects like privacy, knowledge of respondents and response time, revealing the benefits of a hybrid approach.