Long time Dropbox customer. Really like its simplicity and convenience, but a couple things always bothered me: their lackluster command line support, and the fact that they have my files.
Byosynch tries to fix these gaps (first-class CLI support, backing store of your choice, privacy-friendly) while being easy to use.
We currently support macOS and Linux, with an iOS client coming soon.
This is a paid service, designed to finance continued development.
Happy to answer any questions and hear your feedback!