There are few subscriptions in this world which are worth paying for. Fundamental things, and few services qualify. People launching novelty software with monthly subscriptions sounds crazy to me. Just because SaaS used this model successfully up until recently doesn’t make it the right model. You are an indie developer who created an app which can’t in any way of form justify a subscription, you can’t slap on a business model from a venture backed company which needs to justify their existence to investors.