It's a client for syncing files between a PC and a Synology NAS. It is the evolution of the Synology Cloud Station Drive (https://github.com/solus-project/3rd-party/tree/master/network/download/synology-cloud-station-drive).

Name: Synology Drive
Homepage: https://www.synology.com/en-us/dsm/feature/drive
Open Source: no
Link to installer: Synology provide a .deb file: https://global.download.synology.com/download/Tools/SynologyDriveClient/1.1.2-10562/Ubuntu/Installer/x86_64/synology-drive-10562.x86_64.deb