This app is example of how to accept Ethereum ERC20 compatible tokens on ICO.
Logic of function is next - user, which want to participate in ICO for
ERC20 compatible Ethereum token (like FirstBlood
or Chronobank
) must
invoke allow
function for himself on original paybale token contract and then
invoke buyforTokens
function on ICO contract.
This function is checked for allowance
from paybleToken contract, then it
invoke transferFrom
function to ICO contract and provide buy ICO tokens.