Garageband time signatures and tempos
How can you change from one time signature (4/4) to another (3/4) in the middle of a garage band project?
Earlier displays & monitors
You can't do it with GarageBand. You can get around it if you simply manually change your count and provide your own rhythm section with some manual entry. It's all possible, but it is less convenient than with the options available in Logic Pro. I've done it with a little extra work. GarageBand on desktop offers tempo changes, volume and panning changes... things like that.