The app crashes suddenly (video here)

Hey there, Nedim,

Thanks for the message. Looks like you are trying to export screen captured footage. Is that right? If so, you may need better footage to work with as Rush was designed to work with footage from cameras or a qualified mobile device.

Once you are in the territory of screen captures, you need to transcode (re-record or "rip") the footage using the free app, Shutter Encoder on a desktop or laptop computer. The reason being is that it has a big variance in the frame rate, too big for Rush to handle. It's referred to as having a "variable frame rate." Once you have that file transcoded, you can use it in your edit and it should export smoothly.  

Let the community know if this worked for you, if you don't mind. If it does not, also let us know. Good luck with your video!

Thanks,
Kevin