NFScan is a free, open-source software, available to non-profit organizations to receive donations effectively.
Frequent asked questions in Portuguese
Walkthrough in Portuguese
Once you've set up your development enviroment you can make calls to nfscan's public API to process or donate receipts. We've created a wiki page containing all requests you should use in order to integrate with whatever app/site of yours.
We've made an open source app for iOS that integrates with nfscan. You may use it as a reference model or even as a white label product. That's up to you.
You're encouraged to contribute to nfscan. Fork the code from https://github.com/nfscan/nfscan and submit pull requests.
Make sure you're following the contributing guidelines for this project.