Typeblocking is a feature of App Inventor that allows users to type directly on the Blocks Editor to pull up the block they want to use. Normally you find which drawer the block you want is in, then you would have to click on the block and drag it on to the screen. To save time, you can use typeblocking to type which block you want to use right on the blocks editor screen.

Watch the following gif for an example of using typeblocking to make a list using the make a list block.