I am wondering if in this day and age there is a GPS device made that you can take on a plane to tell you where you are at, when flying over places?

I read somewhere that GPS on mobile phones set in 'airplane mode' will still work. But there is a question mark over the accuracy of civilian GPS in that situation. Some airlines might not allow the use of gps devices in any form. There is always a chance it can interfere with the plane's systems.
This is a here-say comment because this is not official advice and I cannot verify the source of the information.

OK, unfortunately I have been on quite a few flights since this was posted due to two deaths in the family one after one. I have found through my satellite tv group on the net that there is a very good independent app available for cell phones now called GPS Status. It takes up very little memory on your phone and is not connected to google or any tracking device or advertisement group. I can say I recommend it. https://gps-status-android.en.softonic.com/android
Since pilots no longer mention where they are now flying over anymore including the Grand Canyon, Yellowstone etc, it is nice to know where you are in the air. It also will tell you your elevation and the speed that your plane is traveling at.
I had to fly Delta, American, United and Eagle and they all said I could use it on the plane no problem. It works best near a window seat but still will work most of the time in an aisle seat.

That message above should be of good use to many of us. Airlines are getting to be quite uncaring to their passengers. We actually had a pilot who really did not know what was below him and took us 600+ miles out of the way on one of our flights home. Steward admitted it was only his second day in the air.