The in-App Flattr button will be tri-state just as its web companion is. There will be no pop-ups though and you will be able to unsubscribe again immediately. A separate menu item will give an overview about all your subscriptions and their status. The switch will show On for active and running subscriptions and it will show Off for paused subscriptions. It will also be possible to delete subscriptions entirely from within the app. That said, you can of course re-add a deleted subscription just by clicking the flattred button for the thing again.
The XCode Project and thus, the resulting App has complete localization support now. The first language the App has been localized to is German. More languages can be added easily and will become available as soon as translators have been found and translations are done. Almost 80% of all Flattr-Manager downloads have been made from the german app store. And as I as the developer am a native german myself, translation was actually a pretty straight forward task. However, adding support for other languages is a little tricky or rather pricey. Paying a professional translator costs between $150 and $300 per language. Donations for Flattr-Manager are nowhere near this numbers so I can only hope for community support.
If you feel up to the task, drop me a line. The current word count excluding doubles and similars is somewhere between to 1500 and 1800.