Get application / file version information.

function GetVersion2(const theFileName: string): string;
var
  VerInfoSize: DWORD;
  VerInfo: Pointer;
  VerValueSize: DWORD;
  VerValue: PVSFixedFileInfo;
  Dummy: DWORD;
begin
  Result := '';
  VerInfoSize := GetFileVersionInfoSize(PChar(theFileName), Dummy);
  if VerInfoSize = 0 then Exit;
  GetMem(VerInfo, VerInfoSize);
  GetFileVersionInfo(PChar(ParamStr(0)), 0, VerInfoSize, VerInfo);
  VerQueryValue(VerInfo, '\', Pointer(VerValue), VerValueSize);
  with VerValue^ do
  begin
    Result := IntToStr(dwFileVersionMS shr 16);
    Result := Result + '.' + IntToStr(dwFileVersionMS and $FFFF);
    Result := Result + '.' + IntToStr(dwFileVersionLS shr 16);
    Result := Result + '.' + IntToStr(dwFileVersionLS and $FFFF);
  end;
  FreeMem(VerInfo, VerInfoSize);
end;

Then get your applications version by calling…

GetVersion2(Application.Exename);