Which Payment platform cost least in donation from mobile devices

[kamii47]

I am evaluating best possible cross platform option of donation via mobile platform. My target devices are at the moment android [primary], IOs and html5 availability with possible windows8 metro devices. Some options are [1, Paypal] [2, Square] [3, Payleven] [4, izettle] [5, Xoom]
Factor should be cosidered as Taxes, Service provider %, International reach possible any Platform or CC charges.
Can somebody help me in it pointing the best possible option​