You need the following components for Work Manager 6.1:
SMP3 SP3 + PL1
SAP Mobile Framework incl. SP3 (ABAP addons SMFND, SMERP and optionally SMISU)
SAP Work Manager 6.1 packages
The WM6.1 packages only became available on SAP Marketplace today; you might have checked before that. (SMP3 and the mobile framework were already available before today)
Regarding documentation: The mobile framework documentation can be found at service.sap.com/inst-guides -> SAP Components -> SAP Work Manager
I haven't found the WM6.1 documentation yet. Seems to be not available so far.