During a recent instrument training flight my instructor had a problem with his iPad that was a new one for me. His iPad started showing a "no sim" message on the upper left side which indicated that the sim card (used for cellular communications and gps) was not working. We removed the card using a paper clip, wiped it off a little and put it back in which solved the problem. The "no sim" issue had prevented the gps from working so the iPad could not be used for additional situational awareness. This might cause an unexpected issue if you felt dependent on it so be prepared if it happens to you. On the subject of situational awareness I have been using the ForeFlight geo-referenced plates option and it is working well for me.  This allow me to see my position on the approach plate.  The following image is what I see when flying an approach.  The blue aircraft icon is my position at the time that image was taken. One thing to note is that your position might be behind the airport view (at the lower right of the plate).  If that is the case the icon will appear over that view but is actually "behind" it on the map.