I'm using Appsheet.com to create my own Android App and it utilises Excel/Google Sheets for charts and information.

I'm trying to create a formula for a certain scenario. I'll try and explain it as best I can.

In Column A I've got addresses.
In Column G I've got the Date.
Column K has an amount in monetary value.

I'd like to consolidate all the addresses within that month into a new cell separated by commas - or better still, by a new line within the same cell. Make sense?
I've managed to sort out adding the amounts into one cell via month using something like this which works out the amount for the month of May 2017.
Code:
=SUMIFS(K:K,G:G,">="&DATE(2017,5,1),G:G,"<"&DATE(2017,6,1))
What would I need to use to do this?
I'm guessing IFS and TEXT along with CONCENTATE perhaps, but after trying to work it out for the day and plenty of googling, I'm getting nowhere.

I reckon it's probably pretty straight forward, but I cannot bend my head around it - or is there an easier way for either that I've missed without the need for the serious programming side of things?