In Germany (part of the EU) the ruling is like this:
An employer has to tell the employee (ideally based in the contract) if company e-mail and equipment is for business use only. This has to be true for all employees.

If an employer does not provide that Information ruling states that the employer has to accept that e-mail and equipment is used for personal matters. The only question here is how much - as in if the employee manages to fullfill his 8 hours of work per day and lets say adds 1 hour personal use.

The tricky part is this:
If the employer allows private usage of e-mail/equipment he becomes a de-facto service provider and has to yield to the law of privacy of correspondence - which means he is not allowed the secretly access equipment or read the e-mail, even if business related

If the employer rules that e-mail and equipment is for business only (s)he can legally read e-mails and access equipment without the employees knowledge.

An additional tricky part is if an employer decides later to cut down on it the employees could claim a right of custom and practice which means it could take months or years before all machines, e-mails and such are clean of private usage. only then the employer would be able to legally access the e-mail or equipment.

Last, but not least, the European Court in question was the Euorpean Court of Human Rights, not the court dealing with the European Union. The participating countries have promised to yield to the rulings in their own private matters, but the ruling limited application as the Court is not part of any justice or executive system in any country of the european union (and more). So it is a court without teeth.

Rereading the question, OP works at a company servicing a SAAS for developers to share code and being paid for it; so far so good. OP works on the backend software for this platform, very well as well.
He wants to sell his Code and Ideas, this is fair. But why has he have to do this in company time? In the question this reads as an imperative? Why can't he do it in his free time like everybody else, using the very same platform he has so much insight in?

Would the code he wants to sell be pertinent to the SAAS platform itself? That might be a bad Idea from the company's point of view for sure.
Or can't he produce non-trivial code one could find on Github or somewhere else in his spare time, because of lack of time or energy or of other reasons like having a life? Well that would mean that he'd work on his own projects on company time, something again any company would find a bad idea for sure as well.

OP's situation is definitely not one of a contractor who writes software or modules from scratch or based on an unique skill-set which is licensed out, and he is NOT producing a product or software in itself, but amends to a (presumably) pre-existing (as in existing at the company before he was hired) software in form of (sic) add-ins presumably ordered by the companies' customers in the first place.
I cannot see a company entering a contractual situation with anyone on these premises unless there would be a BIG benefit for said company.

Don't get me wrong, OP might be a gifted, hardworking, very creative Individual, which could be a BIG benefit for the company to keep and give free reign. But then again as a Company I would argue to advance OP inside its structure, giving a fancy job title, higher payment and so on, as this would benefit the company much more than to allow OP to make money independently from the companies software.

My advise to OP, if (s)he sees him/herself to be a rather free spirit is to break free from corporate shackles and try to stand on their own feet, and create great software, of which one might be the next big thing, get bought by a bigger company and help yourself to those nifty shares!

Otherwise find good use with those good ties to upper management and advance yourself inside the company, working towards the better payday and create some great software, of which one might be the next big thing, go IPO, and help yourself to those nifty shares!

its your choice

It cannot be "saved" or "salvaged" or "restored to former glory" simply because the original 3 Movies live in our childhood memories as these amazing experiences and fantasies and colourful images. No one can create a movie which will compare or surpass your childhood memory.

Even with the argument that the original 3 Movies are still good if one watches them again now, you will just remember or re-live your own personal childhood memory.

Are the 3 Original Movies better than the 3 newer ones? according to my 5 year old son yes - but then again for him it is Darth Vader that sells it. Besides Darth Vader it is Yoda for him in the 3 new movies he loves. Will he think the original 6 movies are by magnitudes better than Part 15 - 18? I am betting everything that he will feel that way.
I am still looking forward to watch every single one of them together with him, because we love the Star Wars, each for his own reasons.

And this sentence illustrates perfectly the biggest issue with the android platform.