What exactly are you trying to do? Are you rooted? Do you have a recovery yet? If that's the case then you can flash roms all day from your phone. If you don't have any of that, there's already been mention of an app called Root Master that roots without a computer. Its not on the play store and it's not in English, so being that I have not used it, I don't believe there's much risk, but read around (root with apk) you can flash a recovery with [root] recovery tools from the play store. Do a google search for the rooting app, if you need it. This forum isn't too large just yet, I'm sure you can find things referencing what I'm talking about.
[ROOT] Recovery Tools-Flasher:
https://play.google.com/store/apps/...s+apk&pcampaignid=APPU_ECFXU524HpCjyAStpIGgAQ
Once you're in a recovery (boot into with Volume down+power buttons or download titanium backup and boot into recovery with reboot options) you will then flash Roms by
First making a backup (optional, but recommended)
[Backup and restore] backup
....wait....
****Do a full clean wipe*****
[Wipe Data/factory reset] yes
[Wipe cache partition] yes
[Advanced] [wipe dalvik cache] yes
[Mounts and storage] format system, yes
format data, yes
format cache, yes
*******To Flash Rom*****
Let's hope it's downloaded
[install from sd card]
[choose zip from sd card]
.....go to the path where you have the Rom downloaded, click it..... then yes to install
......wait.....
Should say finished,
Go back to
[reboot system now]
Congrats!