Fiori apps add-on - Where must we install ? Front or Back End ?

Dear Experts,

We are installing Fiori in NW 7.5 (Front-End) with ERP ECC 6, EHP3, NW 7.31(Back-end)

We are going to use these Fiori apps bellow :

My Inbox

Approve Purchase Orders

Approve Requisitions

We have a doubt about where add-ons must be installed (Front or Back end) SAP_GWFND, IW_PGW, IW_BEP, UIX01EAP 100, GBAPP002 600 or others.

1 - Which add-ons must we install in Front-End(NW 7.5) and Back End(ECC 6 EHP3, NW7,31) for these Fiori apps?

2 - Are there any tips to pay attention or suggest (Basis and Functional) in this implementation ?

Best regards and nice weekend !