I believe it is allowed to use other payment methods when the purchases are not software goods.
For quick capture, I think Drafts could work for you. It is built on the idea of quickly writing things down and then (possibly later) sending them to somewhere else. http://agiletortoise.com/drafts/
Here are design patterns for Java: https://github.com/iluwatar/java-design-patterns
I believe it is allowed to use other payment methods when the purchases are not software goods.
For quick capture, I think Drafts could work for you. It is built on the idea of quickly writing things down and then (possibly later) sending them to somewhere else. http://agiletortoise.com/drafts/
Here are design patterns for Java: https://github.com/iluwatar/java-design-patterns