Incomplete description about network usage
Super Productivity (Free to do list & time tracker for programmers & designers) - link
Just a Webview and entirely depends on their website.
If Data/Wifi disabled, the app shows the error:
Web page not available
The web page at https://app.super-productivity.com/ could not be loaded because:
net::ERR_INTERNET_DISCONNECTED
The application does not have an Offline mode.