I had the same problem. An automatic upgrade rendered my previously functional app unusable. After tapping around for a minute in frustration to try to find some way to dismiss the new subscription screen I deleted the app.
I really do sympathize with the plight of indie developers on the app store but this is too much.
This was fixed in the 2.0.1 update. It came out pretty quick after the initial release, but looks like you hit the unlucky window of having 2.0? If you had Halide previously and download it again it will upgrade you for free.
I really do sympathize with the plight of indie developers on the app store but this is too much.