What you need
A PC running Windows 7 or later, 64-bit. SafeTale installs Microsoft's WebView2 component if needed, used by the journal's text editor.
There is no macOS version, no Linux version and no mobile app.
Installation
Five minutes, four of them waiting.
Download and install
The file is a signed .msi installer. Depending on your machine's settings, Windows may show a SmartScreen warning on first launch: that is normal behaviour for a little-known publisher. You can check the signature by right-clicking the file, then Properties, Digital Signatures tab.
The installation asks for no particular settings. Once finished, SafeTale appears in the Start menu.
Updates
SafeTale checks at startup that it is up to date, and updates itself if not. There is nothing for you to do.
One consequence worth knowing: if the update server is unreachable, the application refuses to start rather than run in an unknown state.