If you're looking for a replacement for Kits, Cryo Mix is another good candidate. It's a collection of AI-based tools for music mixing and mastering. You can upload instrumental and vocal tracks, set parameters and then create final mixes with tools like pitch correction. Cryo Mix's AI Audio Separator can also separate stems from a single audio file so you can work on different elements of the audio.
Another good option is Musicfy, which offers a range of AI-based music tools. Musicfy includes AI voice artists, custom voice creation, text-to-music conversion and stem splitters for breaking down tracks. It also offers royalty-free music albums for projects, so it's good for people with some musical ability or not. The interface is designed to be easy to use, and the service offers a range of subscription plans for those with different budgets.
If you're more interested in audio processing, ai|coustics has more powerful background noise removal, echo cancellation and distortion filtering. It works with multiple languages and accents, so it's good for podcasting, video and e-learning. It offers a simple web app and a range of API/SDK options for building speech clarity into your own products, so you can offer better audio to customers.