Kindle app stuck in landscape mode

[Wotchered]

The heading says it all ! Does anyone remember how to fix this ? I know that I have had this happen before but I can't remember what had to be done to fix it.
Portrait mode on and off doesn't do it nor does a reset, Tiresome !!

 

[Just_Me_D]

What about closing the app, removing it from the app tray, and then more-starting it?

 

[Wotchered]

I found it ! there is an odd fugitive padlock ikon that appears and disappears in the bottom right hand corner of the screen ( more or less where my thumb lives ) You open and close this by tapping it, thereby locking and unlocking the screen orientation. Now all I have to do is to work on my memory for irritating little ikons.