I don't think there's anything wrong with charging, even if you vibe coded it. You clearly put a lot of effort into the design and concept.

As I said in more detail below, on a free tier I expect to be able to at least try it out in a normal way. a monthly limit of exporting 3 pictures (eg to look at on my computer or TV) seems like something a normal person would hit in the first 30 minutes of just exploring what it does. Now, I noticed you run it this way for 14 days, but I gotta say that on first view this was massively outweighed by the 3/month limit.

subscription-wise, I just don't like them. If you are doing a ton of server-side processing, I'd rather pay on an as-needed basis. If not, I'd rather just Pay $19.99 (or whatever price you determine to be competitive in the market for photo apps). I see why subscription income would be nice to have for you, but for me it's a financial leaky faucet. In that case, I'd prefer to just go without because the app is a fun thing to have rather than a professional need.

It also bothered me that it was described as a 'reasonably priced' subscription. If I don't see a $ sign and a number, I reflexively classify it as a scam even though rationally I know you're just testing the waters. I close or dismiss 10 or 20 things a day after a cursory glance into whether they're worth my time or money: fear of being ripped off (FOBRO) outweighs the fear of missing out (FOMO).