For just over a year I've been using Syncthing with a folder specifically for KeePass, and it's worked really well - I just have a raspberry pi running 24/7 so

For just over a year I've been using Syncthing with a folder specifically for KeePass, and it's worked really well - I just have a raspberry pi running 24/7 so my phone and PC pick up the changes whenever I reopen my database. I imagine it's similarly hassle-free with a self-hosted cloud like Owncloud, too.