Add categories/groups to organize items

[aalaap]

I was only using this app to track my streaming service subscriptions, but the screenshot in the README also has other bills like insurance, mobile phone etc. added, which is a great idea. However, the limited number of colors and no other way to group items makes it potentially messy when used for all that.

I'd like to see a label, category, tag or any other such mechanism to simply group together expenses, so we can sort them out into things like streaming, gaming, health/medical, food or whatever we wish.

This would also allow for tracking of expenses for a group as a whole.

[DennisBauer]

I like the idea and had something like that in mind myself.