I remember this blog post (I cannot find right now) where the person split the decryption password in two: half stored on the server itself and half on a different http server. And there was an init script which downloaded the second half to decrypt the drive. There is a small window of time between when you realize that the server is stolen and when you take off the other half of the password where an attacker could decrypt your data. But if you want to protect from random thieves this should be safe enough as long as the two servers are in different locations and not likely to be stolen toghether.
I tried a few and eventually settled on commafeed. It has categories, can be executed from a single docker image (in other words, can run without the hassle of an external database), and the responsive UI works well both on pc and phone.