Mobile learning shows promise but more work is needed. Three projects show what does and doesn't work: 1) A "learning organiser" for university students was used for scheduling but didn't greatly improve learning. 2) "Field trips" using mobile devices engaged students in science inquiries better than traditional classes alone. 3) A low-cost toolkit and guided inquiries on mobile significantly improved science learning versus a control group. More research is still needed on supporting productive learning on personal devices, equitable access, connecting learning across contexts, and lifelong mobile learning.