exhentai mobile
Pre:
Jailbroken device
iFile (file manager, cydia)
Chrome (browser)
e-hentai account with possibly up to 2 weeks on it and possibly some activity?

Do:
Go into chrome, Close all tabs
delete all cookies and data, Restart chrome
go to e-hentai.org and sign in
close the tab, close chrome process
exhentai mobile How to get it? exhentai mobile
open iFile
go to settings (lower left gear) 
open file manager, turn app names on
open /var/mobile/Applications/Chrome/Library/Cookies/cookies.binarycookies (open with text editor)
click edit (top left)
change all e-hentai to exhentai
open browser, go to exhentai.org

You're Welcome - W.L.
exhentai mobile