With this command block setup running in your spawn chunks, your spawn point will be randomized, so when you die, you will spawn up to 250 blocks away in each direction (X and Z) from your last spawn point or bed.

If you just want to try it out, you can download the sample world with the device already running.

To use it in your own world, download the schematic, paste it into your world somewhere in your spawn chunks (around your world spawn) and then hit the button on the side of the bedrock box.

Enjoy your new, slightly more dangerous lifestyle.