The new feature work basically like a bank depositing ur money in it and paying it out with interest.
A little math ^^
260 RPS (originally) => 520 (double)(with interest) / 10 (RPS a week) = 52 weeks = 1 whole year!
So if u have way too many RPS play daily and dont know where to use them them use this feature...
it
offers u to pay a certain amount of RPS (here 260 not sure it is the
same on each account) in the "bank" and seal it and will let u collect
10 RPS a week if u forget them they are gone for ever.... 
260 worthless RPS in hand or 520 on a tree.....hmmmmmmm......
Hope this helped have a great day
