I'm still learning Japanese myself and I have been for 15 months+ and it has been a bumpy ride. But overall a very fun and exciting ride.
If you're just starting to learn Japanese like I did once I think you'd find this very helpful.
Many people use romanji to learn how to pronounce words but as a native English speaker sometimes you'll find that romanji is actually very confusing. When your first starting to learn Japanese it's best to start over from scratch.
The time it takes to learn will almost always depend on how hard and how much you study. Especially Kanji because there are literally more than four thousand words and different meanings. Hiragana should always be the first, because afterwards Katakana becomes a breeze.
( full version is available for both; $4.99. Although still pretty functional)
Andorid Version: Dr. Moku's Hiragana (includes both Hiragana and Katakana)
Android Version: Learning Japanese
Additional: Tae Kim's Website
Very interactive and helpful as well. You can choose the level of Japanese that you are, and it will set up courses for you. Regardless if you don't have an upgraded account.
Android Alternative: They're still working on it but once it's out I'll put the link.
But you can use the website in the meantime.
Android: AnkiApp Flashcards
Android Version: Furigana
Android Version: Nemo Japanese
Google Japanese Keyboard (Android)
Google IME (Windows & Mac)
ASIRadio (Japanese Radio)
Android Version: ASIRadio
Android Alternative: Japanese
Japanese (also available for iphone; $6.99)