Write to rdj@nim.so. Every message is read and answered by me, Robbert Doelwijt Jr., who makes kiek.
Which iPhone you are using, what iOS version it is on, and what you expected to happen. That is usually enough to find it.
If something has gone wrong with a photograph, kiek keeps its own log on your phone. Open settings, scroll to diagnostics, and tap “copy the bench log”. Paste it into the message.
The log records exposures, timings and faults. It contains no photographs and nothing about you, and it never leaves your phone unless you send it yourself.
Apple handles the purchase, so a cancellation or a refund goes through Apple rather than through me. To cancel, open the Settings app on your iPhone, tap your name, tap Subscriptions, and choose Kiek. Write to me anyway if something about it does not look right.