Is Skiley safe?
Yes. More than you think.
We use military-grade encryption and all the industry's best practices to keep your data safe and sound against potential data leaks, hackers, etc.
Please note that we do not have access to your Spotify account's password! We use Spotify's own third-party authenticating system, which implements the so-called OAuth2 architecture that you use in many other apps. Wherever you see those "Login with Google" and "Login with Facebook" buttons, for example -- they all use this OAuth2 architecture.
If you want to, you can delete your Skiley account at any time you want by accessing Skiley > click/tap on the settings menu > Privacy settings... > Delete my account. Furthermore, you can also revoke Skiley's access from your Spotify account, by accessing the Spotify account settings page.