Here are some links that can help to get all the necessary information about FIORI and FIORI HCM Apps.
Fiori Apps Library: The SAP Fiori apps reference library is a comprehensive library of all relevant SAP content for the SAP Fiori launchpad. To know how to use it, please check this video
SAP Fiori Implementation Information : You should select your corresponding version
SAP Product Availability Matrix: You should check with your version and can let you know what of the Apps are available for this version.
2442130 - How to find your User Assistance for Fiori Launchpad
2451481 - How to find your User Assistance for SAPUI5
1797736 - Troubleshooting Guide for SAP NetWeaver Gateway: Please check the file attached to this note.