Contact
Write to miioflee@gmail.com. Every message is read, and most get a reply within a few days.
Reporting a problem with a tool
The most useful reports say which tool you used, which browser and version you were on, what you did step by step, what you expected and what happened instead. If the problem depends on a particular file and you are able to share it, attach it — or a copy with the sensitive parts removed. Because everything runs in your browser, the site has no copy of what you processed and cannot look it up.
Wrong results from a calculator or converter are treated as the most serious kind of bug. If you have a reference value from a bank, a standard or another trusted source that disagrees with a result here, include it.
Suggesting a tool
Suggestions for new tools are welcome, especially for jobs you currently have to upload a file to a stranger's website to get done. Tools are added when they can run completely in the browser and when their results can be checked by tests.