The InfoRapid KnowledgeBase Builder is an excellent tool for Knowledge Management. You can save text documents and web pages with all formattings and links in your knowledge base and perform a full text search in it. Since every document is attached as a text note to a mindmap item, you can organize them perfectly in a large mindmap. This mindmap is browsable, so you will never lose perspective even with thousands of documents. All items are stored in a reliable local SQLite database. The app includes many other outstanding features such as the automatic creation of mindmaps from text documents, the import of Wikipedia articles and Twitter tweets into your mindmap and much more. You can even export your knowledge base as a formatted html document. And that's not all. The InfoRapid KnowledgeBase Builder is also a famous flowcharting tool. You can either create your flowcharts manually or generate them automatically from pseudo code. And there are a thousand more things you can do with the app.
With Family Sharing set up, up to six family members can use this app.