This add-on is a recreation of a popular Java Edition mod that introduces a small window which tells you all the information on the block you are currently looking at.
Select version for changelog:
Changelog
-Added credit to Destruc7i0n for all of the block icons
1. "Download the .mcaddon file"
2. "Open it" by double-clicking the file you just downloaded
3. Minecraft should launch and "the add-on should start importing"
4. Once the import is complete, select Play (At the Main Menu)
5. Either create a new world or edit an existing world.
6. On the left under Add-Ons, select Resource Packs
7. On the right under Available Resource Packs, select "What Is That Stuff" and then click the "+" icon beneath it.
8. Repeat steps 6 and 7 for "Behavior Packs"
9. On the left under "Edit Settings", select "Game"
10. On the right under "World Options", enable "Use Experimental Gameplay"
11. Click Play or Create to complete.