I really like KameSame for vocab SRS. It’s a free tool that was originally created to be a companion to WaniKani, but has evolved into a full fledged vocab SRS. You can put in pretty much any vocab, add your own definitions, and review both recognition and production. The SRS follows the same method as WaniKani (complete with Apprentice-Guru-Master etc levels.)
You can learn more about it here: KameSame - a fast, feature-rich Japanese memorization webapp
A lot of people use Anki, which is more customizable but I find to be confusing to use. I like KameSame because its browser-based and simple to use.