I recently bought a Samsung Galaxy Tab S 10.5 and I am looking for a case where the cover remains open (via magnets usually) when I have it folded back like a magazine (with just the page I'm reading open to me). Right now, all I can find are cases where the cover is left to flop around unless I hold it against the back of my tablet. Are there any cases, brands, manufacturers, etc that make tablet cases with this feature?