metinbana collects nothing, sends nothing and has no account.
A text expander has to see what you type to notice an abbreviation, and has to type to replace it. That is why macOS asks you to allow metinbana under Input Monitoring (to watch the keyboard) and Accessibility (to type the phrase). On Windows the same is done with a standard keyboard hook. Keystrokes are checked against your abbreviations as they happen and then forgotten: metinbana keeps only the last few characters in memory, never writes what you type to disk and never sends it anywhere.
Your phrases live in a small database in the app's own folder on this computer (on a Mac, inside metinbana's sandbox container). A log file next to it records when the app started, errors, and which abbreviation was expanded — never the text you typed and never the phrase it inserted.
Long or multi-line phrases are inserted by pasting: metinbana puts the phrase on the clipboard, pastes it, and puts back what was there before. A phrase that uses {clipboard} reads the clipboard at that moment to insert it. The clipboard is not read at any other time.
metinbana makes no network connections. There is no server, no sync, no update check of its own, and the Mac App Store version is sandboxed without network access.
There is no telemetry, no crash reporting of our own, no identifier and no advertising. If your operating system asks whether to share a crash report with developers, that is its mechanism and your choice.