If you find a bug, feel free to [open an issue](https://github.com/nextcloud/notes-android/issues/new). But please provide these information in the comment:
If you want to contribute on the code, you can fork the project, commit your changes and make a pull request. For bigger features/changes, it's better to first [open an issue](https://github.com/stefan-niedermann/OwnCloud-Notes/issues/new) and ask if this feature is needed or wanted – it would be very disappointing if you add a new cool feature and your pull request will be rejected by some reasons you didn't thought about.