I use an app called

Ham radio Call

which looks up, obviously, ham calls and gives all types of other information and I also use a program called

DXCC

to look up weird prefixes.  I'm getting too old to remember all the new prefixes these days but this little DXCC program works fine.  I also use a little app called

My Altitude.

Denver is, as you all know, called the Mile High City but it is 5,280 feet at a specific step on the capital steppes to the front door and it is downhill all the way to the capital building from where I live on the edge of southwest Denver.  In other words, Denver is in a valley.  According to this program, my house is 5,422 to 5,425 feet.  It changes moment by moment as you move your phone.  No big deal but fun to have as an app to fire up once and awhile.

Note.  If you look for these apps, you might have to run the words together.  I have had them so long, I can't remember how I found them but spaces between words may work as well.

Phil.
K0NX