Hi there @Melisap, welcome to the Spotify Community! Let's try to troubleshoot this issue with you.
First of all, please try a clean reinstallation. This can resolve many common issues.
If you're still having trouble after a reinstall, please let us know the following details:
1. Exact Device (e.g. iPhone 5S)
2. Exact operating system (e.g. iOS 8.3)
3. Spotify app version installed (2.2.0)
4. What are you doing when the app skips/ stops/ crashes? Is it when it opens? When scrolling through tracks? When searching?
5. About how many playlists do you have?
If you could get back to us with those details it would be great. Thanks!