/sdcard/FxDown 

By default, Firefox should use your phone's normal Downloads folder. I don't know whether you can change that, but you can have Firefox use a different one. (Note that this is specifically for downloads, and doesn't affect Firefox's cache of pages or other data, which can be pretty voluminous. I don't know whether there is a way to move that main data folder.) Changing the download location on Firefox for Android requires a visit to the about:config preferences editor. You have to change two different settings to make this work. ''First, you need to know the folder path you want to use. An app like ES File Explorer File Manager will be helpful if you do not have a file manager.'' (1) Open a new tab to '''about:config''' (type about:config in the Awesomebar and tap the go arrow or tap Enter). ''You may want to bookmark this for easier future access.'' (2) In the search box, type '''down''' and tap Enter (3) Scroll down to '''browser.download.folderList''' and tap Modify, then change the value from 1 to 2 (from "default always" to "last used folder"). The change should appear after a few seconds. (3) Scroll back up and tap the large "+" button to the left of the search box to add a new setting (A) The name of the preference should be '''browser.download.dir''' (this stores the last used directory) (B) On the right side, tap Boolean and in the popup change it to String (C) The value depends on the folder you want. For example: /sdcard/FxDown (D) Then click Create (if you are too slow, it may clear and you might have to start again) If you switch back to your other tab and download something, it should go to the new folder. Any luck?