That's so cool, such a nice idea! You should take a look at the Steepshot app if not already done, it suits your posts perfectly. I've never actually used it myself but I've been told that it's very similar to Instagram. It's a different interface for Steem so posts will still be visible through Steemit. Here is a link to Steepshot's website if you want to take a look: https://steepshot.io/