I live in Denmark and have been thinking a lot about this. As far as I know the Danish tax authority regards crypto-coins as trade-objects and therefore not taxable, but you do have to pay WAT (tax on purchases) and you have to calculate that from the price that was current on the day you got it... Not sure about donations like Steemit actually so it is quite a problem. I would very much like such a program (but I am an artist and not a programmer :( )