Crowdfunding Marketing Agency Owner. Raised Over $350 Million on Kickstarter over the past 10 years. Expert at Helping Startups and Entrepreneurs Raise Capital Using Crowdfunding. Host of Art of The Kickstart, The World's Largest Podcast for Crowdfunding. http://www.enventyspartners.com/
Over 8,000 children's books have been funded on kickstarter successfully (https://www.kickstarter.com/discover/categories/publishing/children's%20books). As you look at those that are most funded (https://www.kickstarter.com/discover/advanced?category_id=46&sort=most_funded&seed=2605499&page=1) Like Rebel Girls Series, you can see that successfully building a tribe on the kickstarter platform, can have long-standing positive business growth, by tapping into that community again, for your next book.
There are many resources online that can help. I recommend looking at: https://startupvalue.io/ to give you an idea of how valuations are created based on the problem you've solved.
In the past 4 years of marketing successful crowdfunding campaigns on both Kickstarter and Indiegogo, we've consistently seen drops in consumer traffic to these sites during the holiday months, as potential backers are purchasing products for the holidays that they can gift, not necessarily backing projects/products that will ship next year.
Apps are difficult to fund on IndieGoGo as few are successful, and we rarely take them on as clients. Websites like http://appsfunder.com/ are made for that very reason, but again, difficult to build enough of a following willing to pay top dollar for an app that could very well be free, already existing in the marketplace. A site that is gaining more traction you may want to look into would be http://appsplit.com/. Again, Appsplit Is Crowdfunding For Apps specifically.