End of the counter. That way you could eventually add a fridge surround, and a filler between the upper and the fridge, without an awkward tile gap on the wall.

Should I add tile behind fridge (the wall you can see) ?

I wouldn't. End of the countertop is a logical endpoint for the tile.

Thanks

End of counter.

I think it depends on what you plan to do to end the tile. If this were my kitchen, I would end the tile at end of upper cabinet. Othewise, you'll have to wrap some sort of end treatment above the tile. That above area will be tiny, which I think will be difficult to accomplish. You'll also have to see how much available space you have from the outlet to the end of the tile to see if it all fits. I think my second choice would be to run the tile behind the fridge, that's what I did with my previous kitchen and no one ever paid attention to it, but it was sort of in a inconspicuous area of the kitchen.

End at the counter.