Use data and procedures for different screens

If I program an multi-screen app, I would like to use some variables and some procedures in the blocks of all screens. This seems to be impossible. What a shame. The only way to interchange data between different screens is the TinyDB, I suppose. Do you know any other method ?
It would be usefull as well to use the same procedures in different screens, but I not even can copy them. If the procedure is very complex, it is very much work to make it twice.



you have to take the system with its advantages and disadvantages as it is

instead of using multiple screens, you can always use screen arrangements as fake screens, just set their visibility to false or true as needed. This helps to reduce redundancy.

to pass values from one screen to another, you can use TinyDB or pass them in the open another screen with value block. The value can also be something complex like a list or list of lists

....pass them in the open another screen with value block

This sounds interesting. How can I do that. I haven't found this possibility. 

may I introduce you to the documentation?

http://appinventor.mit.edu/explore/ai2/support/blocks/control.html#openscreenwithvalue

open another screen with start value

Opens another screen and passes a value to it.

Oh. Thank you very much.