when testing my app i found out that sometimes in the simulator everything runs smoothly, but is way too slow on my device. Is there a way to slow down the simulator, so it will run at the same speed as it will run on the smartwatch?
What are things you notice this with? You'll see a difference with things like makeWebRequest, as your computer has a faster link to the internet than a watch with BT and a cell connection. Things that hit the file system will also be slower on the device, so if you're doing a bunch of Sys.println() calls you might notice a difference, and the same if you're referencing a number of different keys in Application.Storage.
For other things, there will be variables, such as how fast your computer is, and what device you're targeting. Petr did a benchmark app a while back that can give you and idea of the difference in running a CIQ app on different devices - the Tree Benchmark. In the description you can see the numbers for many target devices.
There can also be difference based on the FW on the device itself, so things could change just based on what FW.