I'm always reminded of an earlier life. I bought an U/O Beretta shotgun and started rabbit shooting. Could never hit a rabbit. Then once I did, it became easier. The more I hunted, not only did it become more enjoyable, my eye then could see rabbits hiding / camoflaged which I had never been able to see before. But you had to keep hunting and shooting to keep your 'eye' in. Once I stopped for a while, my shooting degraded again.
Something I just thought of, I could also write custom algos for customers, suited to their needs and place it into a cloud folder/file so they could access it anywhere, anytime. I could add suggestions on the better ways to structure it, implement. The customer could edit it or build on it or delete it if they required. In other words I could build the algo and the customer could learn from it and then custom alter it if they wanted or create another one using the original as a type template. Would that idea be attractive?
Not quite sure of the question, can you make a little clearer, what do you mean for example '......or using anything'. You want to know an end application of writing an algo, why I wrote it and the purpose it served?
Algos are like mechanical workshops, you can build whatever you like, depending on the tools within the workshop and your skill level. So you have a workshop with tools and your skills, the next thing is your imagination, what to build, what takes your fancy? So the tools you have to work with for example are: Stock code Stock name Stock sector Current price Open, High, Low, Close, Volume Market Capalization Shares on issue Trade time Trade date Average Volume PE ratio EPS 52 week high 52 week low Price % change Closing price yesterday The currency Some currency and crypto rates From that you can discover: Turnover Average turnover HHV & LLV (Highest High and Lowest low values). Breakouts. Support and resistance levels (depending on you ability to code and the type of S/R) Moving averages, any frequency you wish to imagine. Bullish and Bearish bars. Candlesticks identification and this sort of thing. Bollinger Bands and a bunch of other indicators, you just need to formulate these. Volume spikes and Low volume areas, changes in volume by percentage. You can create buying and selling templates to speed up order executions. You can compare stocks using volatility or ROC. You can find the hottest stocks today or last few days or last few months or years, ie Fastest or biggest movers or on highest turnovers / volume. You can create Sparkline charts - fingernail sized multiple charts on one sheet. You may be seeking either high or low volatile stocks to trade. You may wish to find stocks with the lowest number of shares on issue with the highest volumes. Stocks making new highs or Lows. Discover which stocks are rising while the market is falling & vice versa... The list goes on..... you can virtually create whatever you wish to dream up.
Here's a visual example of something I experimented with once upon a time, but scrapped. The chart is daily chart of Bitcoin with a conventional MA20 (black) and another type of forward looking MA20 (Red) which I created. Actually it's a 1 period MA with an offset. Nothing spectacular about it, but just one of my whacky ideas, but since discovered I think this idea was discovered previously by someone, but I didn't know that at the time. But the idea is a fizzer - useless. All the data was in an algo so I could find the breakouts of multiple stocks.
Here's something I'm currently using, telling me the strength of Crypto. I've left the headers out of this pic. There are yet more fields on dsplay to the right, I've just not included them in this screenshot., like volume, Cap, turnover, etc This is just one of two Crypto algos, the other displays a different view. I use different color coding to indicate different things.
App Script I'm not familiar with that term but googling it, it may be similar but not exactly the same, it is googlechrome, googlesheets, googlecloud. I created an interesting little algo a week or so ago (I thought) which is a volume heatmap which is not just today's heatmap, but a 10 day market heatmap, but volumes only. Again, I use it for market sentiment purposes and imo gave effective results. Just another way of eyeballing very quickly the whole sectors of stocks to ascertain excitement or lack thereof over the past couple of weeks.
Google sheets is the wrong tool for the job. IMO You are way better using any server side programming language and then, if you need a UI use Socket.IO to display any data on a local website. Would you care to describe in bullet points what would be the content of your course and why did you choose Google Sheets over any other platform? A developer wouldn't use Google Sheets for trading, is it fair to say that you are not a developer?