I use mine on the floors all the time, without any hassle from residents or attendings. As a medical student, I'm not sure they'll let you put the EMR applications on the app, but you might as well try if they'll let you.
My essential apps (which includes some iPod apps that don't have an ipad equivalent):
-Medscape
-Diagnosaurus (helps with rounding out your differential and making sure you don't have any D'oh moments when you present)
-Any ICD-9 or 10 depending on if/how your school requires you to log patients
-Medical Spanish (can be a godsend, especially if you review often)
-Instant ECG, iMurmur, and SoundBuilder
-EFM glossary (for when you're on OBGYN)
-iBooks for PDFs of journal articles and textbook chapters (if your library has access to MDConsult or you've set up online access to texts, this is far superior to carrying around a giant stack of papers)
-MD on Call
-AHRQ ePSS (for preventive medicine guidelines)
-Immunization, and GrowthCharts (for peds rotation)
-Evernote, for note-taking and taking pictures of paper notes to store.
-Notetaker HD: for highlighting PDFs.
Other apps that I use, but are probably not as essential:
-inPractice makes some nice "textbook-like" apps. I have the ones for HIV and Oncology. They are published in cooperation with pharma, so consider if you have ideological differences - but they seem pretty straightforward.
-MD ezLabs
-Prognosis: a really fun case-based game where you get the history and physical, and then have to decide what you would do for eval and treatment.
-EyeHandbook
-Board review: TopDoc, Disease Deck, and Distractor Avoidance (which is buggy, but seemed to really help with a few of my shelf exams). As far as DIY flashcards, I'm playing around with StudyBlue and Evernote Peek.
