SaMotion provides with an easy-to-use portable encrypted to-do list.
SaMotion is designed to be a powerful tool for managing your tasks allowing you to concentrate on the most important. It enables you to create lists for use with any situation like movie lists, errands, work tasks, etc. But the best part is that SaMotion offers protection for those bits of data, by encrypting everything with Blowfish 448Bit making them for your eyes only.
SaMotion does give you the option to export your graph as PDF as well. It does offer a few customization features like app docking and light/dark themes but overall just a nice and simple to-do list.