Someone recently suggested to set up a virtual machine where the state of the system can be saved. I've seen it working with other complex programs. No idea about phones, tablets etc but it should likely work on a PC or laptop.
Of course, this kind of saving doesn't allow to save-scum...but it allows interrupting the play.
It was me who suggested the VMs. Well, I've created a Debian VM for VMWare Player (free to download and use but registration required) and compiled a 2.6dev on it. Then moved the to a USB 3.0 Stick. So I always have my 'UFO:OS' with me. At home I use it on my Win7 Desktop and when I'm outside (e.g. visiting parents on holidays) I use it with my Debian Laptop.
Well with VMWare Player it isn't possible to take snapshots of the OS (as I'm used to from the VM Workstation at work) but the OS can be suspended and resumed later without loss of data or game progress.
Regular backups of the savegame files (e.g. cloud storage) are useful in case the stick dies
But all this isn't useful for prqek with his android smartphone. Here the Hibernate software (Sandros post) could be a solution. But I didn't test it.