On top of ethereum nice  inheritance  contract could be  created.
Let say a person A has some  ethereum and  places those  on an inheritance  contract.
In order to keep control of those  coins he need to( let say one per year) trigger function which "says" to it, I am alive do nothing with my coins. In case of  demise or lack of activity contract sends all coins to specified earlier address (or other  inheritance contract) belonging   to person B, whom is from now on, in power  over  those  coins