Cylix is described as 'Secure Productivity Station - Notes, Documents & Databases. Create, organise and centralise documents. Save anything from text, pdf, code snippets, images and videos. Search everywhere regardless of format' and is a Note-taking Tool in the Office & Productivity category. There are more than 100 alternatives to Cylix for a variety of platforms, including Windows, Mac, iPhone, Online / Web-based and Android. The best alternative is Joplin. It's not free, so if you're looking for a free alternative, you could try Standard Notes or Google Keep. Other great apps like Cylix are Microsoft OneNote (Freemium), Evernote (Freemium), Simplenote (Free, Open Source) and CherryTree (Free, Open Source).
Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, can be copied, tagged and modified either from the applications directly or from your own text editor.