I just use Plex. It shows me the next episode on the top. If I stop watching for (I think) 60 days, it drops off Now Playing, but it still remembers if I go back to it, jumping automatically to the next episode.

If you’re on Android, I used to like SeriesGuide. I haven’t used it in over a decade, though, but it came up in conversation and I looked it up, and it still exists. Hasn’t been ported to iOS yet, though, but IIRC it was completely offline.

The MAL stuff is hit or miss because MAL itself is hit or miss.

When you get into online stuff, you tend to run into online problems. Like I know some Sword Art Online fans want the fourth season merged in with the third season. They don’t dislike the fourth season, they just don’t think it should be called the fourth season. They hashed this out on The TVDB, the site that all these other sites pull from, and they lost. Then you have issues like with Bungo Stray Dogs where the first two seasons are put together for some reason — so they’re not always right. But, if you use an online service, you kinda gotta play by their rules, so if those rules become an issue… well… their way or the highway.

You could always just use a note in your phone. I have this app called Hindsight that is kind of a habit tracker. Just for fun, whenever I watch a movie, or finish a video game, or finish a show/season, I log it there. It’s not connected to any metadata provider, it’s just a dumb app that tracks how many times you do something. This is on iOS, but there are tons of these habit tracker apps out there. You can even vibe code them — I don’t endorse vibe coding, but I fell for one first. Apparently whatever AI made them the app couldn’t figure out things like dark mode or other stuff people were requesting and finally they just admitted they vibe coded the thing to make some money. So that is an option, I suppose.