I read through this whole thread and there is a common theme: desktop and mobile. I think the concept of all platforms includes washing machines, toasters, Pi, Arduino, door locks, security panels, smoke detectors, etc. When I look at it that way, I see more than the monitor/keyboard/mouse/monitor(s) setup of a desktop, or the touch/screed/sensors interface of a smartphone.
How would a shopping program work? Could it run in my pantry, refrigerator, washing machine, garage, or anywhere I use consumables? Would each of these be able to communicate so that I can view my shopping list at any time? Would they work with my printer? What about my note-taking program?
Even more, could they send that list to my favorite stores so all I have to do when I arrive is choose perishables like meat and vegetables? Is the store running a scaled up version of the same software? Or maybe running an instance of the software for each customer in a VM?
I imagine a world trending toward Futurama, where everything is a robot of some type, albeit not AI. They can all communicate and take care of my needs mostly without my input. My vacuum knows when to go to work, the floor tells it about the traffic. Other sensors in the floor let the wet cleaner know to clean up a spill. The refrigerator makes sure to stock itself with my favorite drinks, so that they are cold and ready whenever I want one. And since they can all run the same software, I can play Upset Ornithoids on all of them without losing my high score, or take a note and know it will be wherever I am.
It's not about how we can program any one class of device, it's about how we can program all devices at once.