It is commonly known among Zelda fans that the languages depicted and used in the series are actually transliterations of English and Japanese. Many casual fans are unsure of the exact translation (transliteration) process, and ask on various forums about the "correct" translation for whatever is they want. Typically they are interested for tattoos, design work, or other various creative things.
This app simply automates the work of looking up each letter on the chart, and allows you to convert long strings easily. The app also outputs as a png, so it's easy to link and use online. Alternatively you can text (760) 490-0700 with a three letter "tag" to choose the language followed by a space and a string to get the transliteration of that string via SMS.
Translation on the website is supported bidirectionally. English->Hylian works by entering a string into the text box and pressing "translate". Hylian->English works via a virtual keyboard for whichever version you are transliterating. As you tap/click on the letters, the text box will automatically fill in with the corresponding english.