turtl 

Turtl is a client app that connects to a service with the same name, which allows storing different kinds of resources, such as notes, passwords, to-do lists and any type of file. Likewise, it lets you share selected data with other users of the platform.

One of the main benefits you get by using Turtl is absolute privacy and data security. In order to guarantee this, the application creates a PGP key to encrypt everything. This means that not even the service providers can access the contents of the encrypted file. On the downside, it also means that you may lose access to your data if you forget your password.

The application has an easy-to-use interface. In this respect, you can use the plus sign at the lower-right corner to load resources. Most of the time, you will probably use it to create notes, and it is excellent news that Turtl supports using markdown language as well as TeX math rendering.

In terms of organizing resources, a very important element is boards, intended to compartmentalize your information. This way, in addition to the Personal board coming by default, you can also create others to store work-related stuff or just those things you want to share with specific people. What is more, you can nest boards inside others. Luckily, resources can be classified not only by means of boards but also by tagging them.

Turtl requires connecting to a server and it will not work otherwise. Fortunately, you only need to be connected to log in as there is a semi-offline mode. However, it is possible to install your own server, for instance at your office, which also strengthens the security of your data.

All in all, Turtl allows synchronizing and sharing data on different types of devices, as there are clients for most operating systems as well as browser plugins. It provides strong data security, which is reinforced by the fact that the tool is open-source, which means you can inspect its code if you want to. The app is free as well as the basic services. However, should you need more, you can pay for a Premium account.