I have the core feature, whats next?

I have been working on The Paste & Copy (http://www.pastencopy.online) project over a year now. I think 30% of the invested time was for development, 20% for research and design and the rest is for promotion. To my surprise, building it, was easier than getting people to know about it.

Paste & Copy main purpose was to be an easy to use, fast, secure, free & reliable tool to keep strings for copying later on. Tough I use it myself quit a bit, I've probably haven't yet targeted the exact audience. I do get some traffic, but cant get real feedback about audience usage and needs (besides google analytics). I've promoted it mainly through direct contact, Google Ads & Social media.

The "core" feature, as I've mentioned, is complete. User can paste one or many strings, save it in the browser's cache, and easily copy it anytime. No installation, configuration or anything like that. The most important thing for me now, is to find out what might be the "market" needs. what will make people use it more often, for longer periods and recommend it to friends.

Now, I'm reaching out for your assistance - I kindly request that you explore the tool, experiment with it, and share any potential issues you come across. However, what I'm particularly interested in are your ideas for extra functionalities or behaviours that could have a significant impact, such as adding random quotes or a password generator, for example.