http://iscoresports.com/

Runner on first grounder hit to deep second baseman who makes throw to first to but the batter out runner on first is safe at second.

scored in play
location
what happened to runner on first - safe - advanced by batter
what happended to the batter? out, closest thing i see under out menu is force out.

Is this the right way to score the play or is there a better option.

I don't consider this a fielder's choice. A fielder's choice is when the batter makes it to first safe but there's another out. You're saying the batter is out at first.

There are two ways to score it:

The quickest way is to use the built in quick outs.
Swipe the out button and the quick out screen comes up.
Select 4-3 ground out
Location of ball
what happened to runner at first:
safe, second, advanced by batter


The other way is to touch
Out
ground out
location of ball
touch 2B and 1B
what happened to runner at first:
safe, second, advanced by batter

I guess you are right and the app apprears to agree with your assessment. Thanks, always learning!!