Off-peak
Some home tariffs are cheaper for a few hours at night. A ready time, such as 7am, asks the charger to finish before you leave and to prefer those hours. The tariff does the saving. The charger only follows the clock or the signal you set.
The signal
App control needs Wi-Fi or a mobile signal where the unit is mounted. A garage at the back of a house sometimes has neither. Say so on the quote. The survey checks. If there is no signal, you may still charge by plugging in. You may not get schedules.
Load management
This is the charger easing off when the house is already busy, so the supply is less likely to trip. It is a safety and capacity tool, separate from getting a cheap overnight rate.
Prices in the savings calculator let you split charging between a standard rate, an off-peak rate and public chargers. Those prices are illustrative until you replace them.