Only matters far north or south (Scandinavia, northern Canada, etc.), where summer nights get too short for Fajr/Isha to calculate normally. Leave on Default otherwise.
The Islamic date can be off by a day depending on where the moon was sighted. Bump this +1 or −1 if yours looks wrong.
Past 100% the beeps get pushed into distortion so they come out much louder and harsher, all the way up to 1000% if you really can't miss it. Your device's own volume still caps everything.
Needs 🔔 turned on (top-right) and only fires while this tab is open. On phones it has to be the foreground tab, since mobile browsers suspend background tabs and nothing fires while you're in another app or the screen's off. On desktop the tab can sit unfocused or minimized in the background and will still alert.
+Nm gap shown on each row (tap it to edit both). Leave is the big time shown: jamat minus your travel time, so leaving then gets you there right as jamat starts.