You have to download and install Timesheet Android App on your device to use it.
Go to https://apps.apple.com/at/app/timesheet-io/id1488208261 and install the app.
When you first launch the app after installing it, you'll be asked to sign-up for a free account. You start with the Basic (Free) plan. The Data is stored locally on your device, while logged in you can use the app while you are offline.