Is FluentTyper: Autocomplete and Spell Checker safe?

This extension adds autocomplete, spell checking, and text expansion while you type in Chrome.

It suggests words and phrases in real time across most websites, lets you accept suggestions with the keyboard, and underlines misspellings with correction suggestions. You can also create custom shortcuts for frequently used phrases such as templates, replies, snippets, addresses, links, and repeated responses. The store description says it works offline and does not upload keystrokes, track users, require accounts, or collect data.