Our Wal-Mart delivery service is called Spark here in the USA. I signed up for it, but I'm stuck on a waiting list.
There will always be people who are cheap and feel like a low tip is acceptable, luckily the app gives you an idea of what that customer usually tips before you accept the batch.
I wouldn't be doing this if I was stuck with specific hours. The flexibility is the best part.
Thanks bro!