Support
Write to support@longlight.app with any question about Longlight. Below, the questions the app's pages do not answer.
Does Longlight need an account?
No. There is nothing to sign up for. The app runs on your devices, and iCloud sync, if you turn it on, uses your own iCloud account.
Is my data private?
Yes. Nothing you enter leaves your devices. The privacy policy has the details.
Which devices does it run on?
iPad, iPhone, and Macs with Apple silicon, where Longlight runs as the iPad app in a window. One purchase covers all of them, and a plan syncs between them through your iCloud if you choose.
Where do the tax rules come from?
From IRS publications, Social Security's regulations and the other documents on the Sources page, 160 in all, each with its edition and date. The figures in them, the brackets, deductions, limits and tables, are kept in a few versioned data files apart from the code and checked against the documents by hand.
Can I get my plan out?
Yes. The whole plan exports as a JSON file and imports back the same way.
What happens if Longlight stops being developed?
The app on your device keeps working. It needs no server. Your plan is a file you can export at any time, and the methodology on this site is enough to reconstruct every result from it.
Is this financial advice?
No. Longlight is an educational and informational tool. Everything it shows is a hypothetical projection built from the numbers and assumptions you enter. Before acting on anything it helped you think about, verify the numbers independently and consider talking to a qualified professional: a fee-only fiduciary advisor, a CPA, or both.
Contact
Write to support@longlight.app.
This site is set in your device's own system face, San Francisco on Apple devices, with Nunito, under the SIL Open Font License, standing in for the app's rounded figures. It is static pages and one stylesheet, with no script and no analytics. The screens are the app's, captured in Apple's simulators. The How it works page is generated from the text the app ships, the Sources page from the repository's list of source documents. Longlight is made by one person, and each rule in it comes from a document you can read.