Young black men who have sex with men (MSM) bear a disproportionate burden of HIV. Rapid expansion of mobile technologies, including smartphone applications (apps), provides a unique opportunity for outreach and tailored health messaging. We collected electronic daily journals and conducted surveys and focus groups with 22 black MSM (age 18–30) at three sites in North Carolina to inform the development of a mobile phone-based intervention. Qualitative data was analyzed thematically using NVivo. Half of the sample earned under $11,000 annually. All participants owned smartphones and had unlimited texting and many had unlimited data plans. Phones were integral to participants' lives and were a primary means of Internet access. Communication was primarily through text messaging and Internet (on-line chatting, social networking sites) rather than calls. Apps were used daily for entertainment, information, productivity, and social networking. Half of participants used their phones to find sex partners; over half used phones to find health information. For an HIV-related app, participants requested user-friendly content about test site locators, sexually transmitted diseases, symptom evaluation, drug and alcohol risk, safe sex, sexuality and relationships, gay-friendly health providers, and connection to other gay/HIV-positive men. For young black MSM in this qualitative study, mobile technologies were a widely used, acceptable means for HIV intervention. Future research is needed to measure patterns and preferences of mobile technology use among broader samples.