Most of these so-called modern apps on Windows 10 is rubbish, when I was using ten I replaced them all with my normal ones. some of them I use is getting on, but they do the job.
Even the calculator is awful, i never did find one that looked like the one that is in use in Windows 7 and 8.
Yes, the picture and fax viewer is in Windows 10 and yes it is a shame MS have hidden it, i suppose they want us all to use their modern apps.
Desktop machine now powered by windows 8 pro 64bit, no dreaded metro and Linux , laptop by Linux