Notes app trust it’s so reliable it’s where I have my list numbered and everything
Anilist and Manga-Updates is a good place, you can also use MAL. alternatively I have a spreadsheet to keep track of my lists since it's more personal that way but can be time consuming to setup. (I mostly do the spreadsheet method since you can add hyperlinks to where you're reading the story)
I use an app called mangapin that can access stories on multiple platforms and keep them in a single library together
I store it in my brain and hope for the best
i’m so tired of losing my lists on these sites anyone have any alternatives where i could easily keep track across multiple sites?? it doesn’t have to connect to the site directly or anything i just need somewhere i can add them to lists in one place that is actually reliable