Google Sheets is an amazing way for me to keep track of my crypto portfolio, as well as how much and where it's invested or held.
It's nice to see a live updated price for my portfolio net worth, similar to using the GoogleFinance() function to return the almost live price of stocks. I am currently using the GDAX API to query the last traded price for each cryptocurrency listed on the site, and then stripping away the extra characters in the response to be able to use the price as a numeric value.
To get the price of BTC in USD, I have this formula in the google sheets cell:
=VALUE(SUBSTITUTE(SUBSTITUTE(INDEX(IMPORTDATA("https://api.gdax.com/products/BTC-USD/ticker"),0,2), "price:",""), """", ""))
Replacing the 'BTC-USD' with 'LTC-USD' or 'ETH-USD' will return the last traded price for either of those trading pairs.
I'm also able to track any coin that is listed on coinmarketcap.com using a similar function. For example:
=INDEX(IMPORTHTML("https://coinmarketcap.com/assets/omisego/","table",0),2,5)
returns the USD value of OMG. To track any other currency, it just involves copying the URL from coinmarketcap into the IMPORTHTML() function.
I've been blown away with how much benefit there is in using google sheets over excel with the ability to get live data (may be delayed by up to 15 min). I briefly looked at what it would take to implement the same kind of functionality in excel, but external data connections are required, and the entire process is much more involved than copying a formula to a cell in Google Sheets.
Hope someone finds this information useful.