As long as your pull request doesn't break the app in any way or conflict with an ongoing change (check the open issues first or send me an email to make sure this doesn't happen), it will likely be accepted. I have a lot of projects and may not get around to reviewing pull requests right away. If you have contributed to this project before and would like to be added to this repository as a collaborator, feel free to send me an email and ask.
I don't use branches because I'm lazy. If you want to make a branch, feel free to do so, just be aware that I will completely ignore it and push my changes to master anyway, because I'm special.
yep.
This project uses the last.fm API to fetch album artwork, so you will need to get an api key and add it to the strings.xml file as <string name="last_fm_api_key">YOUR_API_KEY_HERE</string>.