I would like the trading analytics in the share dealing account's to visualise account balance over different time scales with the P/L e.g 1 day, 1 week,1 month, 1 Year. Dividend payment calendar with the payout amount ( show previous payments in another chart). One platform which I have seen which has lots of chart's is M1 Finance.
Fractional Share's especially on the larger tech stock's such as NFLX, GOOGL, AMZN.
To trade option's on individual stock's.
To be able to buy cryptocurrency in a ISA account or cryptocurrency ETF's.