I can't decide between another year at $100 or switching to two years for $180. The saving doesn't feel quite enough. And I don't know how long I'll be doing this for. Maybe forever. >_<

Monthly. After all, you never know if the app is still going to be around in two years time. For now, it's broken and unusable on my iPad.

2 years. USD80 for second year is 20% discount, but would need to get a return of more than 25% in a year on USD80 to justify delaying on economic grounds: assuming you are sure will need to add words continuously over the next two years. I think there should be a 5 year or "lifetime" option too.

Han82 - if you don't like broken operating systems/apps from time to time I recommend you wait 1 month + after release until update, first adopters always sort out the bugs, and I thank them for that. I will move to OS8 in a month or so probably. But don't wait as long as much of China, chugging along on Windows XP.

Ricksh, good advice but a bit too late for me. By the way, there's nothing good about iOS 8 so don't move to it at all if you can. There are no features worth risking your device for. My iPad now feels like a cheap android tablet from China. This isn't something I expected from Apple.

I'm on the monthly plan as long as i'm on the discounted price. half year payment after that probably. They should continue the discount as long as the android app is in beta *wink*

I would love a lifetime pricing plan :)