A potentially simple, but useful tool… If you pay into multiple ISAs a year from your personal account, you could tag the payment or have a separate ISA saving category. This would then create a little widget that would show a progress bar going up to the £20k limit allowed each year. This could then reset each tax year.
Any provider of an ISA account has this progress bar but they are siloed and do not talk to each other. Having it done directly within the account you send money from to the ISA means you can keep track. Thoughts?