You don't need an app to learn Hiragana. I studied Japanese in college and started in a summer class.
Learning hiragana was a requirement before starting day 1.
To be honest it only took a few hours and all we had to do with was a few pages of photocopied writing pages with some mnemonics. Now you can just download the equivalent, or even get a full guide with videos: https://www.tofugu.com/japanese/learn-hiragana/
Seriously, hiragana/katakana are one area where you don't need a hack. For learning how to actually understand the language, then you'll need to buy books/CDs/Podcast subscriptsions/classes/etc...
