Create an online interactive staff development record

I want to create an online system (including an app) where my team members can log into the app and add evidence of their professional development. The system will have individual's names, roles, and professional development statements to match evidence against. The evidence can be added by way of written statements, voice notes and videos. Colleagues should have the ability to send peer assessments to managers for inclusion on the peer's development record.
The system must have the ability to add new staff members and be able to update role statements.
The system must be owned by myself and for me to have access to all back-office functions.
I've almost created this using google forms, but it's become too technical for me!!