I don't call regularly but I do maintain my own catalogue of dances which I transcribe in Word and often subsequently save as PDF. I also have a (very professional. lol) grocery store produce bag of printouts that I carry around. I prefer a piece of paper in my hand but have called from my smartphone as well.

I put the folder of all my contra files in the cloud, most recently OneDrive. By doing that, the files are accessible on any device with net access. On my own devices, I can set the folder to be available offline (i.e. stored on the device) should I not have net access.

Unfortunately, not all cloud products are created equal and functionality in the same product is sometimes different from platform to platform (e.g. phone vs laptop), so be watchful.