Locally trusted CA certificates circumvent HPKP protection, because many organisations use TLS MITM attack to spy on their staff and browsers must support it in order to work properly in those environments. But it makes sense for browser. If you are making your own application, you can implement it in any way. Simplest way would be to embed public key in the application and check it without HPKP. Though, probably, if your app is popular, you'll face that in some networks your connections are MITMed and you (or user) can't do anything about it, so it's choice about dropping security or not to work at all.