I'm learning about Android apps by developing an RSS reader for Inoreader. The API can be found here
This app won't work without developer keys being added to gradle.properties. You can get keys by creating an application in the developer section of the Inoreader preferences. The format should be:
InoreaderAppId=xxxxxxxxxx
InoreaderAppKey=xxxxxxxxxxxxxxxxxxxxxxxxxx
CsrfProtectionString=xxxxxxxxxxxxxxxxxxxx