As I own some btc and have done for a while I'd like to contribute to the network some how but am not in a position to keep a PC on 24/7 to run a node..
Running a node isn't really that altruistic in regards to contributing to the network, the main purpose of running a node is to verify your own incoming transactions. If you want to contribute, a great way to do so is to test open source software for busy devs. Finding bugs, or even giving general feedback, helps figure out the roadmap for their software.
I have Blixt Wallet, Zeus Wallet, and Phoenix Wallet on Android. The first two are for power users, the last is for newbies who just want good UX.