Thanks for posting this article. OK and NEO staking looks pretty fine to me 
ok lets say i have 50 NEO's how much i'll get interest? any number of %
For NEO, you do not have to run your computer to stake...you just need to use their approved wallet. It will generate GAS on its own at roughly 10% per annum rate (NEO to GAS ratio). There are calculators online if you want to find out the exact rate.
ARK is a DPOS coin and once you put your coins in a private wallet and vote for a delegate, you earn ARK through your delegate at around 10% per annum also. Last I checked mine, the return is closer to 12.6% if I recall correctly. You do not need to run your computer to stake DPOS coins.