[Someone]

Ah! Thanks. It might be worthwhile to mention in the FAQ that not this does not run on all devices running iOS 9. The App Store description shows a list of supported devices, but because of the fragmentation of the iOS market :-), it is so long and incomprehensible that I don't bother to read it.

And no, I don't think "requires a 64-bit CPU" is sufficient to describe it.

[LeoNatan25]

I guess they are assuming that if you are installing a content blocker, you are tech savvy enough to know what CPU the device you own has. I agree this is a problem. This is a transition period. Most likely iOS 10 will be 64-bit only, so these kind of problems will get worse before disappearing altogether.