When using ERPNext’s Calendar on an iPhone (5s, personally) in Chrome or Safari, the last line of the month is cut off and doesn’t allow for any scrolling. I’m not sure if this is a result of the drag functions of the calendar that negate the ability to scroll down the page.
Side:note, I noticed that when customizing columns for reports, it allows the user to create, drag, and re-arrange, but can’t change the field name.