Next steps after launch...

According to PH guidelines and from my 5 years of experience in sales, you should always follow up with your customers. Based on the number of upvotes on your launch page, I'm assuming you've got at least 300-500 new users. This number is absolutely manageable for personalized outreach - emails work fine in my opinion. If you have some internal analytics that will help you understand if the user did some kind of an activity using your app, of if they just registered and left - follow up accordingly. For those who didn't fully understand the UX and didn't convert through the whole user path as you originally designed, then you could ask why they left and maybe you could help with instructions / hints. If they did what you wanted them to, you can ask them for their feedback and try to discover what would make them want to return to your app and become recurring users or paying subscribers. For the team of 2-3 people - 300-500 users is one week's job, but it's better to assign it as a priority to the marketing / business dev / sales people. But if you're a small company, I think it's worth spending the time on it of everyone on the team. The early adopters can have power to attract new users via the word of mouth, so I'd invest time and effort to ensure that they are satisfied. It's not scalable and at some point this marketing communications should be automated to some extent, but I personally think that during the early stage this human-to-human approach is the best.