I've released a small update that adds the ability to project your time to financial independence. It is based on the Networthify early retirement calculator with some extra tweaks. Given an initial "stash" amount of your savings and your expected future expenses, it will estimate the time to reach FI with an expected return. It considers you FI when it covers your expenses by an extra 20%.
This is nowhere near as powerful as other projections but in future updates I'll be tieing into your savings a lot more, such as being able to track your net worth. I wanted to get something in your hands sooner rather than later because I kept having to use other tools to get a quick estimate.
I also plan to allow you to bucket into taxable, non-taxable, HSA, etc. with different expected returns, which is what my Excel worksheet can handle. This also does not take into account a target withdrawal rate. In other words, expect this to evolve over time!