Email vadapalas.zigmas@gmail.com. One person reads it, usually within a day or two.
Spelli uses the voices built into iOS. Higher-quality ones can be downloaded on the iPhone under Settings, Accessibility, Spoken Content, Voices, and picked in Spelli's Settings under Voice. For a word the voice will never get right, record it yourself: tap the word in the list, then Record. Adding a sentence to a word also helps with words that sound alike.
It should not be. Spelli's test field switches off autocorrect, predictive text, spell checking and automatic capitals. If a third-party keyboard still shows suggestions, switch to the standard iOS keyboard for the test using the globe key.
Capital letters do not count unless you switch on "Capital letters must match" in Settings. Spaces at the ends are ignored. Everything else has to match the word as it was typed into the list, so check the list for a typo first: tap Edit words.
The free plan keeps one list at a time, with no limit on the words in it. Tap the plus button and choose Replace: the new list takes the old one's place. Spelli Pro keeps every list.
Settings, Restore Purchases, on any device signed in with the same Apple Account. The purchase is handled by Apple; refunds are at reportaproblem.apple.com.
Recordings are stored only on the device that made them. They are not backed up to Spelli's servers, because there are none. Deleting the app deletes them.