Tachiyomi app has become the most popular manga reader among manga fans after Mangarock is not working.

Here is the list of best Tachiyomi extension based on my experience:

1. MangaDEX: This is the most popular extension. it has the Fastest manga updates and good quality images. Also, it has the latest releases.
2. Mangakakalot: is the largest manga library. Simply, all the manga are available here to read, Also this has some manga that you cannot find on other sources, for example, Goblin Slayer.
3. MangaSee: If you are looking for high-quality images, Mangasee is the extension you are looking for. And also it has official translations.
4. MangaHUB
5. MangaPark