on android its easy
you just use tinifile
and use
e.g
myifile:=TIniFile.Create(GetHomePath+'myini.ini');
on iOS
I use the units
Apple.IniFiles, Apple.Utils
(google search for these authored files by a well known pascal developer/supporter)
and then declare as
e.g
myifile:=TuserIniFile.Create;
i.e no name
and when using, there is only 1 field
e.g
mystr:=urlinifile.readstring('mydata1','');
instead of
mystr:=urlinifile.readstring('mysettings','mydata1','');
and use the idef blocks so same code can be used
i,e
{$IFDEF iOS}
//code
{$ENDIF}
or
{$IFDEF Android}
//code
{$ENDIF}