Oye donde esta el bloque

[Taifun]

Use the clock component

And for better understanding why there us no block "repetir para siempre" read this

A Single Thread of Execution in App Inventor Screens (mirrored)

Additionally the following information from @Franklyn_A_Turbak is helpful to understand the model of event processing in App Inventor (taken from here) Taifun When a block execution e a bit long, all the display are executed at the end of th execution of the block. Suppose you want to inform the user that the action he started may take some minutes !... When the code is executed The first message (on the title bar in this example) Must be shown before the begin of the loop execution ! [unk…

Taifun