Suggestions:
Include the language code when uploading xml files. I always have to look up the codes. Google does this with their service[1].
An option to default to Show All. Or a url parameter. Every time I refresh the page or press back, I'm in pagination again.
When drilling into a particular language, show the language in the header title. It just says "Localize". Makes having various tabs open troublesome.
Use the language code in the url. Right now, it's... https://www.localize.im/projects/abc/languages/3C when it should be https://www.localize.im/projects/abc/languages/ru
Automatic translations.
Paid translations.
[1] https://www.dropbox.com/s/z5382q9grbyl30f/Screenshot%202014-...