Recent surveys show that mobile apps are more popular than Web apps. Apple's iTunes Store, now has about 800,000 apps and reported to have about 40 billion downloads. Android apps, although fewer, is available to the most number of smartphones today. About 40,000 apps are medical or health related. We developed a PubMed4Hh mobile app for iPhone/iPad users to search MEDLINE/PubMed with same features as our Web-based search tools, in use since 2002. Five-year (2008-2012) server data for PubMed4Hh and Web app were analyzed. Searches using the mobile app significantly increased compared to the same five-year time period. Month-by-month comparison showed a 3 to 5-fold increase in queries. The six-month total accesses comparison increased 280% from the previous four-year average. A review of 500 randomly selected queries revealed that the majority of queries were clinical questions ((97.8%) and 61% of these queries are searches related to therapy.