Browse Marvel Unlimited by Year
This site allows you to see what issues are available on Marvel Unlimited for a given year. Tap the comic's cover to be taken directly to the comic in Marvel Unlimited or the web-based reader, depending on your device. If you're on Android, you may have to use the issue's title link instead to launch the app. You can also filter the available issues for a given year by series, creators, or events.
Note that some of the pages may use up quite a bit of data due to the size of the API response and the images. Each cover image is about 13KB, so a year with 1000 comics released will use up approximately 13MB of data. Tread carefully if you're on a mobile device with a limited amount of data.