Hi Michael,
It depends. You need to go to Fiori Apps Library and view details each app that is of your interest here.
You can see what are the backend prerequisites for each of the app and need to make decision.
You need to go to,
Implementation Information -> Backend Components -> Prerequisites for installation.
For example, "My Leave Request" requires your backend to be at one of these or above.
EHP2 FOR SAP ERP 6.0 - SPS 05 (02/2009) or
EHP3 FOR SAP ERP 6.0 - SPS 04 (02/2009) or
EHP4 FOR SAP ERP 6.0 - SPS 02 (02/2009) or
EHP5 FOR SAP ERP 6.0 - SPS 01 (06/2010) or
EHP6 FOR SAP ERP 6.0 - SPS 01 (11/2011) or
EHP7 FOR SAP ERP 6.0 - SPS 01 (08/2013) or
SAP ERP 6.0 - SPS 15 (02/2009)
Regards
Krishna