This Monsta FTP is very easy to use, just upload it to your webhost and done, you can use it! I would reccomend this app because its lighty and very simple. It still has some features need to be add.

Note being able to save FTP credentials was the one big drawback for me. Probably wouldn't be too hard to add a localstorage option or something if somebody had the time as the source looks quite readable and clear. Other than that, the script performs a charm. Definitely the best web-based FTP script of the several I've tried.