Do you ever complete the earn credit offers on Habbo? I know they've been around for years and some of them can be a bit sketchy or cost, but I started doing them on an alt account (mainly for safety and to see how many I could earn) a couple of months ago and I'm at 64 credits so far. This is just from downloading apps and reaching the levels they say, I'm currently half way through one. Don't get me wrong a lot of them take a lot of time which I haven't got most of the time so I just get to the first stage if they're multi level ones as 1c or something like that is better than nothing. What's good as well, whatever credits you earn you also get diamonds as well - so if you earn 10c you get 10 diamonds too. If you're thinking of doing some though, I would just stick to the free ones that way Habbo/the offer doesn't profit off you or anything!
Have you done any that have worked?