This app was mentioned in 1 comment, with an average of 6.00 upvotes
The whole subject is very difficult. By your argument pretty much every app with In-App purchases would be illegal. These usually don't tell you what exactly works in the free version and what requires extra money. This is morally questionable, possibly false advertising, but most certainly not illegal.
And unfortunately the "If they want money just make it a paid app in the app store" doesn't really work. FIBRUM aren't the only ones that published a roller coaster. I bought the Lava Coaster, and the Cmoar Roller Coaster gets better ratings than the FIBRUM coaster and looks a lot better (on a faster phone). It is available for EUR 4.27, 30% of which goes to Google, and has sold between 1000 and 5000 copies. It has been in this range since at least March, so they most likely got a number of sales due to the attention for their VR viewer kickstarter in February and not much since then. The free demo, which is much shorter, has 10K-50K downloads. Cmoar have invested a lot into VR, and I doubt that they did recoup the costs for developing the coaster. Most people would rather spend an hour hunting down a free copy than spending even USD 0.99, and here we have a discussion how to obtain illegal copies of a once free roller coaster instead of pointing out the existing alternatives. Thanks to the app stores for mobile software there has been a race to the bottom for prices, with zero being the only acceptable price for many. One consequence is that now it has become close to impossible for new developers without huge marketing budgets to succeed with games that are not following the Freemium/In-App sales model.
We've had a number of discussions on /r/GoogleCardboard about the options for developers to make a living with VR software, and so far it doesn't look good. Pretty much the only two categories making money are virtual cinema apps and the use of Cardboard in promotion, either by producing customized Cardboard clones or VR experiences for some marketing department. If this doesn't change, nobody should complain that there is a lack of good VR software that is more than just a short demo. If we want better VR software, we will have to make some kind of contribution to the developers for their time and work. Standing on a box and crying foul because something that was once free now no longer is doesn't really send an encouraging signal to other VR developers.
I won't deny FIBRUM the right to try to make some money for their work, I just despise the removal of functionality without warning and the excessive privilege demands. Without doubt they produced a lot of great looking apps that actually worked even on slower phones. This took a considerate effort, due to the amount of apps they created they probably spend much more time developing Cardboard apps than anybody else. So they aren't going for a least-amount-of-work money grabbing approach and deserve to earn something for their contributions. They just should find a way for this that doesn't make them look like jerks.
A better approach than sharing unlicensed versions of FIBRUM apps would be to look for and point out alternatives. This is of course inconvenient and difficult due to the dire state of VR software, but it would hurt FIBRUM a lot more if nobody mentions them anymore and might get them to rethink the situation. It would also entice other developers to fill the gap. Having discussions that the FIBRUM apps are so good that people look for ways to steal them is actually promoting them.
Edit: typos, fixed links