You can purchase ready-to-run add-on developments from PREISS Consulting for some typical requirements. The add-ons work in SAP ERP and in S4/HANA They are based on ALV techniques and use SAP standard functions (BAPI, API) to read and change SAP objects whereever possible. The coding is well documented and structured so that it can be adpated easily, also from your developers. I could deliver versions with Fiori user interface if needed.
Please contact my with your questions or price inquiries or if your are interested in similar developments.