LinkedIn: This is also a free tool where you get to upload your CV and other profile information about yourself. You get to network with professional people, chat and discuss issues related to work, projects and other worldly issues. Even if you retire, your professional network stays intact and you still get to keep in touch with professionals.
Summing up, these five free digital tools are what you should retain for keeping in touch with friends, acquaintances and professionals and grow your networks to a large extent gradually and feel further inspired and empowered.