Don't count out immersion so easily. check out
this siteit is pretty awesome how this guy learned. he replaced everything he could with japanese. Immersion especially with a language as close to your own as "Norske" works the best. Immersion doesn't mean packing up and moving to the country. It means being exposed to the language every day.
ex. Wanna watch a movie? watch it with norwegian dubs instead. except don't watch it with english subtitles because if you use subtitles you don't start thinking in that language and it only teaches you to read english faster.
ANYWAY best software I have found is
anki it takes some dedication but it is the fastest way i've found to learn a large vocabulary. also you might want to pitch in a bit of money and buy yourself a textbook. I don't know what ones are good for norwegian but make sure you get college ones that a lot of learners can back up to its quality. The last thing you want to get is a bi-lingual dictionary, and after you have a vocab of about 200-300 words get a monolingual dictionary. It helps you find words you want reletively fast.