These are more like suggestions than feature requests, but I think they would be a welcome addition.

1. I see that if the same word appears multiple times on a page, it is sent to be translated twice.
For example, for two select dropdowns, you may see this in the URL: &q=Select&q=Select

The way the translations are fetched should be re-worked so that the request isn't made twice (now that both the Google and the Bing API are subject to strict limits and payments)

2. If a translation fails because a usage limit is reached, show the original text instead of blank strings.

3. Don't remove tabs and indentations from the source code. This doesn't improve performance and only makes the source harder to modify or build upon by those of us who like to dabble in PHP.