You can do this yourself for free, using the U2NET model... Either client-side or server side.
https://github.com/xuebinqin/U-2-Net
Pretty trivial thing to implement.
https://github.com/xuebinqin/U-2-Net
Pretty trivial thing to implement.
How to send and receive image between linux and iphone is left as an exercise for the reader.
Open source implementation of this
That said, I am not negative, only pointing out that at least for me (as a admittedly non-native speaker,) trivial is not a word I would use to describe it.