My niece recently started nursing school and I have given her a few options, some of them free. Free and useful: micromedex drug information, medscape. Epocrates has both free and paid versions, and offer trials that you are not bound to purchase after trial ends. I highly recommend both Unbound Medicine and Epocrates. Sometimes you need to flip between the two depending what you are looking for. I did not care for Pepid, but many do. I am still seeking an effective toxicology app, but that's another story... Also paid apps I like are, pedi safe, (designed like the braeslow cart, acls and pals advisor whick incorporate cpr guidelines.