For hosting common files it's ok. Also it is on Android too do, great to transfer files between your Windows and your phone. But if you want better security you have to subscribe a monthly offer.
Dropbox - Online Sync and File Sharing
Joplin - 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, tagged and modified either from the applications directly or from your own text editor.
Google Drive - Access and sync your files anywhere
OneNote - Get the OneNote app for free on your tablet, phone, and computer, so you can capture your ideas and to-do lists in one place wherever you are. Or try OneNote with Office for free.
Mega - Secure File Storage and collaboration
Standard Notes - A safe place for your notes, thoughts, and life's work