Set the rent up once
Rent, wifi, the cook and the maid cost the same every month, so nobody should have to type them in every month. In a Kitna Hua flat, turn on Repeats monthly when you add the rent, then pick the day it's due and the first month.
Early in the morning on that day, India time, the server adds it as an ordinary expense, split the way you set it up. It goes in even if every phone in the flat is switched off. A bill due on the 31st goes in on the last day of shorter months.
Bills that change every month
Electricity and gas are never the same twice. Set them up as monthly bills and leave the amount empty. On the day, whoever pays gets a reminder, and tapping it opens the expense with everything filled in except the amount.
Not everyone uses everything
If one flatmate eats out and never touches the cook's food, split the cook among the people who eat. If one room is bigger or has the balcony, split the rent by exact amounts or by shares instead of equally. Either way you set it once on the monthly bill, and every month after follows it.
Settle at the end of the month
On the evening of the last day of each month, everyone who isn't square gets one notification saying what they owe or are owed. Simplify debts shows the fewest payments that clear the flat, and the pay button opens your UPI app with the amount filled in.
Moving in and moving out
Someone leaving settles up first. The flat's owner then removes them, and they drop off every monthly bill from the next one. Someone new is added by the owner, who then edits each monthly bill that should include them, since bills don't add new people by themselves.
The total
For the four flatmates below, October comes to ₹77,100. Rohan, who skips the cook, pays ₹17,025 and the other three pay ₹20,025 each. Aditi paid the rent, so three UPI transfers to her settle the month.