Our Furuno chart plotter includes high resolution satellite photos that can be overlaid on the charts with varying transparency (plus with radar to boot). These photos are updated as regularly as the charts. I would be surprised if Furuno is the only one doing this.

Our Nobeltec charts also have satellite photo overlays.

There is free software that automatically downloads Google Earth data, geo-references it to your chart data and overlays it with varying transparency. Using it with the free OpenCPN charting program makes this ideal for the budget.

I don't know about tablet and phone apps since we haven't gotten that far into the future yet. But it seems like a silly easy thing to do.

In our cruising areas, the charts are highly inaccurate. We are pretty much navigating off Google Earth and electronic charts I make myself from pictures in chartbooks. Don't laugh - this combination is highly accurate. Definitely (and literally) miles more accurate than the current commercial charts. Also, I bet they would be more accurate than the best charted parts of the US - particularly around constantly shoaling areas.

Mark