The Spanish "future progressive" is formed using the formula below:

future of estar + present participle of the action verb = future progressive

The Spanish future progressive - el futuro progresivo - is very similar to its English counterpart (will be + -ing). In both languages, the future progressive expresses an action that will be in progress at a certain point in the future.

Cuando vengas estaré leyendo unas revistas.
When you come, I will be reading some magazines.

Papá estará leyendo un libro.
Dad will be reading a book.

Mi familia estará pensando en mi.
My family will be thinking about me.

El Sábado ellas estarán haciendo tartas de calabaza.
On Saturday they will be cooking pumpkin pies.

El jueves mis gatitos estarán yendo al veterinario.
On Thursday my kitties will be going to the vet.

Ellos estarán jugando un partido de fútbol el sábado.
They will be playing a soccer game this saturday.

The future progressive is similar in usage to the future, but with an emphasis on the fact that the action will be in progress at the moment in question.