PayPal
PayPal is the big dog of the online payment processing world and has come up with secure mobile apps that are very useful for affiliates. The ability to safely send and receive payments from your mobile devices is exactly the kind of thing that makes life easier for busy affiliates.
Whether you need to get money to contractors or transfer cash to your land-based accounts, it can all be done directly from this app.
The PayPal app is available on both Android and iOS and seems to be favorably reviewed by users.