I made the app open source as one customer emailed me asking for the code, hoping to make some changes. When first releasing the app (v1.0.0) I was worried about making it open source (perhaps someone would steal it) but after almost a year 'on the market' it seemed safer. I don't know how common it is for that fear to materialize in reality, but at least in my case it seems like no one made an identical copy (or even a similar copy for that matter) and started distributing it (my other fear was someone creates a virus-ridden copy).

Making the app open source improved it significantly: the customer who asked for is initially contributed some excellent code making screenshot extraction better (and faster). Others have added bugfixes or features. I'm really glad I did it. I also gave a talk touching on the open source question at AngularNYC in February (still waiting for the recording to be put up on YouTube).

PS -- my app is Charityware - I wrote a blog post about that too: https://medium.com/@whyboris/charityware-doing-good-with-pro...