Come back to coding with a project for myself

Hi All,
I have been tossing around an idea for a simple mobile app for a while. It is something I want to have for personal use. My first thought was to wait for someone else to build it, but haven't seen anything. My second thought was to hire someone to do it. But I kept coming back to the thought of tinkering on my own and get back into programing and learning.

I started my career as a C++/Java programmer and really enjoyed it but burned out working for large corporate dev shops. I hated it so much that I left the industry and started a new path that involved zero coding work.

So much has changed since I last did any dev work (pre-iPhone), but I am curious to learn again and dive in. I'd like to believe the "fundamentals" I learned are still somewhat relevant, but I guess I'll find out. Coming back to where I started this post I thought I'd "learn by doing" something I want to build for myself. I have no time pressure and no customer to please but myself.

I know a lot of what I'll be doing is starting from scratch, but I am looking forward to the journey and hope I can lean on this community for guidance, motivation and support. Thanks in advance and if anyone has any suggestions on how to best start, or resources to consider...etc I am all ears.