5 best Memex alternatives in 2021

Memex is a bookmark manager with the following features: tags, full website text search, folder sharing, ios app, android app, importing/exporting, automated backups, privacy-based.

Here are some great alternatives.

Trove is a privacy focused bookmark manager built on Blockstack, which is a de-centralized Blockchain. It is encrypted and provides a minimalist UI design.
Turtl uses powerful cryptography to encrypt your bookmarks to make them more secure. The user interface is visual-based and resembles Pinterest.
Hush let's you save bookmarks from incognito mode in Chrome.
LinkLocker is a privacy focused bookmark manager that is completely private and has an API.
WebCull is a privacy focused way to organize your bookmarks that uses Stacks which are essentially folders in a list.