If you have a business that is likely to be capital intensive, I would raise seed capital as early as possible. Sure, some VCs want this and some Angels want that, but that's a generalization and you could certainly find the right investor with enough diligence to seek them out.

Before you seek funding you need to ensure you're buttoned up with your business plan and proof of concept. If you're app is new, but carries some similarities to others, then use that competitive knowledge to frame up the opportunity for an investor. A savvy and aggressive investor doesn't need to see every nut and bolt to evaluate an opportunity, but they do need to gain an understanding of where you fit into the market place in order to have a perspective on market potential. Good luck.

Without fully diagnosing the market potential of your space it's difficult to say whether to go all-in or change course. It's smart that you're not wanting to the "just another ordinary software", but you don't need to be the best per se. You simply need to be unique - which may prove challenging when providing a utility. If it were me, I would sell what you have like crazy and potentially offer the service at a lower rate to start with based on the expectation to clients that you are in the midst of integrating new improvements. This would allow you to onboard them earlier to generate cash flow, then increase the cashflow once the new features are built in. Since I don't know the full scope of what you're doing I could be off base in that clients either want it all or nothing, but if the latter is not true I would sell, sell, sell and offer unrelenting service which may prove to be part of your uniqueness. Good luck.

First off, I'm sorry to hear of your struggles. Secondly, I commend your diligence. As for which course of action to take... There is no silver bullet and while it may seem frustrating you may very well be right on the heels of success. You never know when it will take place in your life, but if you work hard, smart and long towards a clear goal you will get there. I would avoid bouncing from one opportunity to the other as it is difficult to hit a tipping point if you're spreading your activities too thin. Best of luck to you.