Expense tracker

I find it hard to keep track of what I spend, because I never really use to keep track of things I spend, I usually have a set amount of money that I set for myself to be the cap for each week, and living here in Hong Kong has been especially hard for me to keep track of how much I spend, because everything seems so cheap and affordable here, If it wasn't for work, I would be buying things everyday, a little bit here, and a little bit there.

I think i have to write everything i spend down.