I'm not sure if this is how you imagine this world to work, but at least according to the order you wrote it "raising funds" was first. In reality it should actually be one of your final steps of the stage you are at right now. It may even come after a year or two!
So you have this great app idea, and you're looking for a place to start... Don't! Don't start yet before you decide whether you have what it takes to get into a roller coaster that can ruin your life and make you miserable! Not trying to scare you but I think most people only hear about these great success stories. They have this dream of maybe, possibly, becoming the next big thing... Because they have the best idea for an app... You don't hear about the failures so often. And even if you do, you don't hear about what the founders of these failing startups had to go through.
Truth is you are most likely gonna fail. And I'm saying that without even knowing what your idea is. There are so many barriers on your way that even a great product with a great team is likely to fail. Some people would say "I'm not afraid of failing", "It's good to fail cause you learn", "Failing will make me stronger for the next startup". That's somewhat true but it doesn't mean that failing is easy. As oppose to what people sometimes say - you do not want to fail! It's very painful!!!
You have to understand what failing in a startup means. You can work your a$s for 2-3 years, have little to no salary, waste other people's money (most likely your friends and family first), lose friends, fight with your partners, your family, your spouse, devote 20 hours a day for your startup all this time, forget about the little and big things you used to enjoy in life, and only then, after debating 100 times whether you should quit or not, you finally decide that it's not gonna work and you've failed. Disappointing your family, your investors, yourself. Trust me it is painful.
Are you sure you wanna do this to yourself?
If yes, give me a call. I have the experience you need! From idea stage, to proof of concept, to running beta tests, getting millions of millions of users in ways you can't even imagine, creating features and experience that will make these millions of users completely addicted and viral, raise money in a smart way, hire the right people, find a great co-founder, succeed, fail, be persistent, and enjoy the ride!