Have a balance slider or 100% button for all fractional number input fields

Description:

I’ve got to transfer/swap/buy/sell 0.000013

Purpose:
No one wants to type that. Espesically if they can’t see their balance on that screen.
You force your user to go back out, get a crayon write their balance down go back into the swap screen reselect the token and then type in the decimal value sometimes with lots of 0
Humans are bad with doing tasks like that.

A slider to select a fraction of your balance to buy/sell/swap would make the use case usable.

Extension/Mobile/Both:

Mobile

Images/Attachments: